Stereoendoscope wherein images having passed through plural incident pupils are transmitted by common relay optical systems

ABSTRACT

The illuminating light transmitted by the light guide inserted through the elongate inserted section is projected out of the distal end surface of the inserted section. The illuminated objects pass through the respective pupils of the two objective lens systems arranged in parallel within the distal end section of the inserted section and their images are formed on the focal surface. The respective images are transmitted to the rear side by one common relay lens system. The transmitted final images are formed respectively on the image taking surfaces of the image taking devices. The respective images photoelectrically converted by the respective image taking devices are processed to be signals, are displayed in the monitor and are stereo-inspected through shutter spectacles.

This application is a divisional of Ser. No. 09/053,094 filed Apr. 1,1998, now U.S. Pat. No. 6,306,082 which is a divisional of Ser. No.08/404,890 filed Mar. 16, 1995 which has issued as U.S. Pat. No.5,743,846.

BACKGROUND OF THE INVENTION Field of the Invention and Description ofRelated Arts

This invention relates to a stereoendoscope wherein images having passedthrough plural incident pupils are transmitted by common relay opticalsystems so that an observation providing a stereo-feel may be possible.

Recently, particularly in the surgical field, there is noted a so-calledendoscope operation wherein, in order to reduce the burden on thepatient, without opening the abdomen, a small hole is made in theabdominal part, an endoscope is inserted through the hole for theobservation and treatment. In this field, the operation has been alreadymade by directly seeing and stereo-observing the affected part with botheyes and therefore, even in the endoscope operation, thestereo-inspection is strongly desired. If the stereo-inspection can bemade, the operation will be easy, the operation time will be reduced andthe burden on the patient will be further reduced.

As a stereo-inspection endoscope whereby stereo-inspection is possible,there is a first related art example suggested in a Japanese patentapplication No.309078/1992 shown in FIG. 1A wherein two exactly the sameoptical systems are arranged in parallel and the images formed by theobjective optical systems 401 and 401′ are transmitted for apredetermined distance by the transmitting optical systems 402 and 402′(in this case, relay lens systems) and are taken by such image takingdevices 403 and 403′ as CCD's.

The taken pair of the right and left images are converted to electricsignals and are displayed in a TV monitor not illustrated. At this time,when the displayed right and left images are switched at a high speedand simultaneously shutter spectacles synchronized with the images areused, the image for the right eye will be observed with the right eyeand the image for the left eye will be observed with the left eye so asto be able to be stereo-inspected.

Also, as another type stereoendoscope, there is a second related artexample suggested in a Japanese patent application No.28278/1993 shownin FIG. 2A wherein the objective optical system 414 and the relay lenssystem 415 which is a transmitting optical system are formed of oneaxially symmetrical optical system. A prism 416 is arranged at the rearend of the relay lens system 415 and a pair of right and left imageshaving a parallax are formed and taken in the the image taking devices417 and 417′ by spatially dividing the pupil into two with the prism.FIGS. 1B and 2B on the left side of FIGS. 1A and 2A show respectiveincident pupils.

In order to make a stereo-inspection, it is necessary to obtain a pairof right and left images having a parallax from each other. Therefor,the incident pupil for the right image of the optical system and theincident pupil for the left image must be positioned as spatiallyseparated. Also, the magnitude of the stereo-feel in the case of thestereo-inspection is proportional to the center distance between theright and left incident pupils.

In the two above mentioned related art examples, in the case of thefirst type in which the same two optical systems are arranged, when theobjective optical systems 401 and 401′ to the image taking means 403 and403′ are separately formed and the left and right incident pupils 407and 407′ are separately positioned, images having a parallax from eachother will be obtained. The center distance d between the left and rightincident pupils 407 and 407′ coincides with the optical axis distance Dbetween the left and right objective optical systems 407 and 407′.

In the second type in which the pupil is divided among the abovementioned related art, the objective optical system 414 and transmittingoptical system 415 are formed of one axially symmetrical optical systemand the pupil is one in this part but, when this one pupil is spatiallydivided into two by the pupil dividing means (in the above mentionedcase, the pupil dividing prism) 416 and respective images are produced,images having a parallax from each other will be obtained. The centerdistance d between the left and right incident pupils 418 and 418′ is ½the size of the incident pupil 419 of the objective lens.

In the type in which the same two optical systems are arranged, as it isformed of separate right and left parts, the number of the parts is highand the assemblability is low. Also, the magnification differencebetween the right and left images due to the errors of the respectiveparts is large, the displacement of the focusing position is large, thenormal stereo-inspection can not be made and therefore a fine adjustmentis necessary.

In the type of dividing the pupil, there are advantages that the partscommon to the right and left light paths are many, the number of partsis low and the displacement of the right and left images can be madelittle. On the other hand, when compared with the same thickness, themagnitude of the parallax will be smaller than in the first type and asufficient stereo-feel will be hard to obtain. That is to say, there isa problem that the center distance between the right and left incidentpupils is hard to make large. This point shall be explained withreference to FIGS. 3A to 4B.

FIG. 3A shows as magnified the objective optical system on the distalend side of the first related art example. FIG. 3B shows its incidentpupil. Also, FIG. 4A shows as magnified the objective optical system onthe distal end side of the second related art example. FIG. 4B shows itsincident pupil.

In the type in which the same two optical systems are arranged, that is,the first related art example, against the inside diameter Φ of theobjective lens frame 421 of the endoscope distal end 420, the opticalaxis distance between the right and left objective optical systems issubstantially Φ/2. Therefore, the center distance between the right andleft incident pupils 407 and 407′ is also substantially Φ/2.

On the other hand, in the type in which the pupil is divided, againstthe inside diameter Φ of the objective lens frame 421 at the endoscopedistal end 420, the diameter of the incident pupil 419 of the objectiveoptical system is smaller than Φ, because the incident pupil of theobjective optical system is smaller than the pupil of the relay lenssystem as the NA of the endoscope is limited by the outside diameter ofthe relay lens system and the picture angle of the objective opticalsystem is larger than of the relay lens system.

Therefore, the center distance between the right and left incidentpupils is smaller then Φ/2 and is usually about Φ/6 to Φ/10. Therefore,in this type, the magnitude of the parallax is about ⅓ that in the abovementioned type. Particularly, in case the distal end is thin, nosufficient stereo-feel will be obtained.

OBJECT AND SUMMARY OF THE INVENTION

In view of such circumstances, an object of this invention is to providea stereoendoscope wherein, as in the type in which the pupil is divided,the parts common to the right and left light paths are made as many aspossible, the variations of the right and left images by the productionerrors or the like can be made few and images having a stereo-feel by aparallax as large as of the type in which the same two optical systemsare arranged are obtained.

The stereoendoscope of the present invention is characterized bycomprising an objective optical system which has plural incident pupilsformed in different positions and forms plural images having passedthrough these plural incident pupils and having a parallax from eachother and a common image transmitting optical system which transmits theplural images having a parallax from each other.

When thus formed, as the objective optical system has plural independentincident pupils, irrespective of the size of the diameter of theincident pupil of the objective optical system, the parallax will beable to be made large. Also, as the plural images and pupils are notseparately transmitted by the plural transmitting systems but aretransmitted by the common image transmitting optical system, the numberof parts will be able to be reduced. Even if a production error ispresent in the individual image transmitting optical system, as theimages are transmitted by the common image transmitting system, thevariation between the plural transmitted images will be able to bereduced.

In order to realize such formation, there are the following two systems(a) and (b):

-   -   (a) A formation comprising an objective optical system which        forms plural images having parallaxes in spatially separated        positions and one image transmitting optical system which        transmits the plural incident pupils and the plural images of        the object optical system so that the images transmitted by this        image transmitting optical system may be taken finally by one or        more image taking means. More concretely, it is as in the        following:

A stereoendoscope having an objective optical system, image transmittingoptical system and image taking device, characterized in that theobjective optical system comprises plural optical systems arranged inparallel and forms plural images having a parallax from each other andthe image transmitting optical system comprises an optical systemarranged along one optical axis and transmits plural images formed bythe objective optical system.

In this formation, as the operation common to (a) and (b) is made andthe image transmitted by the image transmitting optical system is alsospatially separated, the image can be stereo-inspected through an imagetaking means taking images or an ocular optical system makingobservation with the naked eyes. The image taking means can use one ormore image taking devices and can take plural images transmitted andspatially separated by the transmitting optical system andstereo-inspection is thereby possible.

The other formation realizing such formation is as follows:

-   -   (b) A formation comprising an objective optical system forming        plural images having parallaxes where they spatially        substantially coincide (superimposed), jetting pupils        corresponding to the plural incident pupils of the objective        optical system and one image transmitting optical system        transmitting the plural images, wherein the images transmitted        by the image transmitting optical system are taken finally by        one or more image taking means.

More concretely it is as follows:

A stereoendoscope having an objective optical system, image transmittingoptical system and image taking device, characterized in that theobjective optical system comprises plural front group optical systemsarranged in parallel to take in plural images having a parallax fromeach other and rear group optical systems arranged so as to be on thesame optical axis as of the image transmitting optical system andforming images of beams from the plural front group optical systemswhere the beams are substantially superimposed and the imagetransmitting optical system transmits the plural images formed by therear group optical systems, having a parallax from each other andsubstantially superimposed and the jetting pupils of the objectiveoptical system.

In this formation, as a common operation is made and images havingparallaxes are transmitted to be formed where they are substantiallysuperimposed, the diameter of the relay optical system can be madesmall.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show a first related art example. FIG. 1A is a formationview showing its stereoendoscope. FIG. 1B is an explanatory view showingincident pupils.

FIGS. 2A and 2B show a second related art example. FIG. 2A is aformation view showing its stereoendoscope. FIG. 2B is an explanatoryview showing an incident pupil.

FIG. 3A is a magnified sectioned view of an objective optical systempart on the distal end side of the first related art example. FIG. 3B isan explanatory view showing incident pupils of FIG. 3A.

FIG. 4A is a magnified sectioned view of an objective optical systempart on the distal end side of the second related art example. FIG. 4Bis an explanatory view showing an incident pupil of FIG. 4A.

FIGS. 5 and 6 relate to the first embodiment of the present invention.FIG. 5 is a formation view showing the whole of a stereoendoscopeapparatus provided with the first embodiment.

FIG. 6 is a formation view showing an image taking optical system in thestereoendoscope of the first embodiment of the present invention.

FIG. 7 is a formation view showing an image taking optical system in thesecond embodiment of the present invention.

FIG. 8 is a formation view showing an image taking optical system in thethird embodiment of the present invention.

FIG. 9 is an explanatory view showing an arrangement example of an imagetaking device.

FIGS. 10A and 10B relate to a modification of the third embodiment. FIG.10A is an explanatory view showing images formed by an objective opticalsystem and relay optical system and a final image by the imagetransmission.

FIG. 10B is an explanatory view showing the arrangement of a final imageand an image taking device arranged in the position in case theobjective optical system and relay optical system of FIG. 10A are used.

FIG. 11 is a formation view showing an image taking optical system inthe fourth embodiment of the present invention.

FIG. 12 is a formation view showing an image taking optical system inthe fifth embodiment of the present invention.

FIG. 13 is a formation view showing an image taking optical system inthe sixth embodiment of the present invention.

FIG. 14 is a formation view showing a main part of an image takingoptical system in the seventh embodiment of the present invention.

FIGS. 15A and 15B relate to the eighth embodiment of the presentinvention. FIG. 15A is a plan view showing an objective optical system.FIG. 15B is a side view showing the objective optical system.

FIGS. 16A and 16B show the ninth embodiment of the present invention.FIG. 16A is a plan view showing a unit formation of the ninthembodiment.

FIG. 16B is a side view of FIG. 16A.

FIGS. 16C and 16D show a first modification of the ninth embodiment.FIG. 16C is a plan view showing a unit formation of the firstmodification.

FIG. 16D is a side view of FIG. 16C as an ocular adapter is connected.

FIGS. 17A to 17C are explanatory views respectively showing unitformations in the second to fourth modifications of the ninthembodiment.

FIGS. 18A to 18E are views respectively showing formations of objectiveoptical system units.

FIGS. 19A to 19D are views respectively showing formations of relayoptical system units.

FIG. 20 is a formation view showing an image taking optical system inthe tenth embodiment of the present invention.

FIG. 21 is a formation view showing an image taking optical system inthe eleventh embodiment of the present invention.

FIG. 22 is a formation view showing an image taking optical system inthe twelfth embodiment of the present invention.

FIGS. 23A to 23D show a meniscus lens in a modification of the twelfthembodiment. FIG. 23A is a sectioned plan view. FIG. 23B is a side viewas seen from the side of FIG. 23A. FIGS. 23C and 23D are respectively afront view and back view as seen respectively from the front surface andback surface sides.

FIG. 24 is a formation view showing an image taking optical system inthe thirteenth embodiment of the present invention.

FIG. 25 is a formation view showing a main part of an image takingoptical system in the fourteenth embodiment of the present invention.

FIGS. 26A and 26B show an objective optical system in the fifteenthembodiment of the present invention. FIG. 26A is a plan view. FIG. 26Bis a side view.

FIGS. 27A and 27B show an objective optical system in a modification ofthe fifteenth embodiment. FIG. 27A is a plan view. FIG. 27B is a sideview.

FIGS. 28A and 28B show an image taking optical system in the sixteenthembodiment. FIG. 28A is a plan view. FIG. 28B is a side view.

FIGS. 29A and 29B show an image taking optical system in the seventeenthembodiment. FIG. 29A is a plan view. FIG. 29B is a side view.

FIGS. 30A to 30G are explanatory views respectively showing unitformations of the eighteenth embodiment.

FIGS. 31A to 31F are views respectively showing concrete formations offront group units.

FIGS. 32A to 32F are views respectively showing concrete formations ofobjective optical system units.

FIGS. 33A to 33D are sectioned views respectively showing formations ofrear group and relay lens system units.

FIGS. 34A and 34B relate to the nineteenth embodiment of the presentinvention. FIG. 34A is a general formation view of a stereoendoscopeapparatus provided with the nineteenth embodiment.

FIG. 34B is a view of the arrangement of an objective optical system onthe distal end surface of the stereoendoscope of the nineteenthembodiment.

FIGS. 35A to 35C relate to the twentieth embodiment of the presentinvention. FIG. 35A is a view showing the formation of a stereoendoscopeof the twentieth embodiment.

FIG. 35B is an elevation showing the arrangement of an objective opticalsystem as seen from the distal end surface.

FIG. 35C is an explanatory view showing the arrangement of an imagetaking device as seen from the distal end side.

FIGS. 36A to 36F show the formation on the distal end side of thetwenty-first embodiment of the present invention. FIG. 36A is avertically sectioned view. FIG. 36B is an elevation of FIG. 36A.

FIG. 36C is a horizontally sectioned view.

FIG. 36D is an elevation of FIG. 36B

FIG. 36E is a horizontally sectioned view.

FIG. 36F is an elevation of FIG. 36F.

FIGS. 37A and 37B show the formation on the distal end side of thetwenty-second embodiment of the present invention. FIG. 37A is avertically sectioned view. FIG. 37B is an elevation of FIG. 37A.

FIGS. 38A and 38B relate to a prior example. FIG. 38A is a formationview showing the formation of an objective optical system in astereoendoscope of the prior example.

FIG. 38B is an explanatory view of a power arrangement for the objectiveoptical system of FIG. 38A.

FIGS. 39 to 42 relate to the twenty-third embodiment of the presentinvention. FIG. 39 is a general formation view of a stereoendoscopeapparatus provided with the twenty-third embodiment.

FIG. 40 is a formation view of an image taking optical system includingthe objective optical system in the stereoendoscope of the twenty-thirdembodiment.

FIG. 41 is an explanatory view of a power arrangement of the objectiveoptical system of FIG. 40.

FIG. 42 is a sectioned view showing a frame structure at the distal endof the stereoendoscope in FIG. 39.

FIG. 43 is a formation view of the objective optical system and imagetransmitting optical system relating to the twenty-fourth embodiment ofthe present invention.

FIG. 44 is a formation view of the objective optical system in thetwenty-fifth embodiment of the present invention.

FIG. 45 is a formation view of the image transmitting optical systemincluding the objective optical system in FIG. 44.

FIGS. 46 to 48 relate to the twenty-sixth embodiment. FIG. 46 is ageneral formation view of an endoscope apparatus.

FIG. 47A is a formation view of a plural visual field direction typeendoscope.

FIG. 47B is a view showing the formation of a brightness diaphragm.

FIG. 48 is a formation view of an objective optical system utilizing apupil division.

FIGS. 49A to 54 relate to the twenty-seventh embodiment. FIG. 49A is aformation view of a plural visual field direction type endoscopeincluding an objective optical system utilizing an eccentric opticalsystem. FIG. 49B is a formation view of an endoscope relating to amodification of the twenty-seventh embodiment.

FIG. 50 is a formation view of an objective optical system in which aneccentric optical system is utilized and an afocal part is partly incommon.

FIG. 51 is a formation view of an objective optical system in which aneccentric optical system is utilized and a perspective is made byrefraction.

FIG. 52 is a formation view of a design of an objective optical systemin which an eccentric optical system is utilized.

FIG. 53 is a formation view of a design in which a relay lens system iscombined with an objective optical system.

FIG. 54 is an elevation of an objective optical system having threevisual field directions.

FIGS. 55 to 58 relate to the twenty-eighth embodiment. FIG. 55 is aformation view of a plural visual field direction type endoscope havinga pupil switching apparatus.

FIGS. 56A and 56B are formation views of a plural visual field directiontype endoscope in which the visual field direction can be switched by animage rotator.

FIG. 57 is a formation view of a plural visual field direction typeendoscope in which the visual field direction can be switched by themovement of a solid state image taking device or the like.

FIG. 58A is a formation view of a plural visual field direction typeendoscope in which a pupil switching apparatus is provided near thepupil of an objective optical system.

FIG. 58B is a formation view of a plural visual field direction typeendoscope different from that of FIG. 58A.

FIG. 59A is a formation view of a plural visual field direction typeendoscope relating to the twenty-ninth embodiment. FIG. 59B is aformation view of an endoscope in which the objective optical system ismade partly common.

FIG. 60A is a formation view of an optical system of a plural visualfield direction type endoscope of the thirtieth embodiment.

FIG. 60B is a formation view of an optical system of a plural visualfield direction type endoscope of a modification of the thirtiethembodiment.

FIG. 61A is a formation view of an optical system of a plural visualfield direction type endoscope of the thirty-first embodiment.

FIG. 61B is a formation view of an optical system of a plural visualfield direction type endoscope of a modification of the thirty-firstembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention shall be concretely explained in the followingwith reference to the drawings. The stereoendoscope in each of the firstembodiment to the twenty-second embodiment is characterized by having anobjective optical system which has plural incident pupils formed indifferent positions and forms plural images having passed through theseplural incident pupils and having a parallax from each other and acommon image transmitting optical system which transmits the pluralimages having a parallax from each other.

Each of the first embodiment to the modification of the ninth embodimentis of the formation (a). That is to say, images having a parallax fromeach other are formed in separated positions by plural objective opticalsystems arranged at the distal end of an endoscope and the imagesseparated from each other are transmitted by one image transmittingoptical system becoming common.

As shown in FIG. 5, a stereoendoscope apparatus 1 comprises astereoendoscope 2 of the first embodiment having an image taking opticalsystem for stereo-inspection built-in, a light source apparatus 3feeding an illuminating light to an illuminating light transmittingmeans provided in this stereoendoscope to transmit the illuminatinglight, a camera controlling unit (abbreviated as a CCU hereinafter) 4processing signals for an image taking means built-in in thisstereoendoscope 2, a scan converter 5 converting the signal from thisCCU 4 to a video signal, a color monitor 6 displaying the video signalput out of this scan converter 5 and shutter spectacles 27 having ashutter function for stereo-inspecting the image displayed in this colormonitor 6.

The stereoendoscope 2 has an elongate inserted section 11 to be insertedinto a body cavity or the like and a gripped section formed to be largein the diameter at the proximal end of this inserted section so as to begripped by the operator. This inserted section 11 is formed of acylindrical rigid jacket tube made of such metal as stainless steel.That is to say, this stereoendoscope 2 is a rigid endoscope having therigid inserted section 11.

The same as an ordinary endoscope, this stereoendoscope has anilluminating light transmitting means transmitting the illuminatinglight fed from the light source apparatus 3, an illuminating opticalsystem projecting this transmitted illuminating light out of anilluminating window and illuminating the object side and an observingoptical system obtaining two images having a parallax so that the objectilluminated by this illuminating optical system may be stereo-inspected.

By the way, in this specification, this observing optical system ismostly explained in an embodiment acting to form two images having aparallax on an image taking device provided with a photoelectricallyconverting function and is therefore also called an image taking opticalsystem.

The gripped section 12 is provided with a light guide mouthpiece 13 anda light guide connector 15 at the other end of a light guide cable 14removably connected at one end to this light guide mouthpiece 13 isremovably connected to the light source apparatus 3.

A lamp 16 generating a white illuminating light and a lens 17 condensingthis white light are arranged within the light source apparatus 3. Theilluminating light condensed by this lens 17 is radiated on the endsurface of the light guide connector 15, the illuminating light radiatedon this end surface is transmitted by the light guide within the lightguide cable 14 and the transmitted illuminating light is fed to thelight guide 18 side within the stereoendoscope 2 from the light guidemouthpiece 13.

The light guide 18 as an illuminating light transmitting means is bentwithin the gripped section 12 and is inserted through the insertedsection 11. This light guide 18 transmits the fed illuminating light andprojects the illuminating light forward from the distal end surfacefixed to the distal end 19 of the inserted section 11 and furtherthrough an illuminating lens 20 fitted to an illuminating window.

The respective optical images (represented by reference numerals 7 a and7 b in FIG. 6) of the object (represented by the arrow in FIG. 5) 29illuminated by this illuminating light are formed in image formingpositions by objective optical systems 21 a and 21 b fitted to twoobserving windows arranged adjacently to the illuminating window withinthe distal end 19. The two objective optical systems 21 a and 21 b areof the same formation and are formed of optical lenses preferably of thesame characteristics.

As shown in FIG. 5, the two objective optical systems 21 a and 21 b havethe respective optical axes Oa and Ob in parallel with the center axisof the inserted section, are arranged in parallel on both sides of thiscenter axis and are separated from each other by d in the distance(interval) between both optical axes Oa and Ob. Also, both optical axesOa and Ob are arranged as separated in the diametral direction crossingthe center axis and are therefore arranged symmetrically with the centeraxis. Two optical images large in the parallax can be formed by theobjective optical systems 21 a and 21 b of the same formation with theoptical axes arranged in parallel as separated by the distance d betweenthem.

The images 7 a and 7 b are formed, as shown in FIG. 6, in separatepositions by the two objective optical systems 21 a and 21 b and aretransmitted rearward by a common relay optical system 22, that is, oneimage transmitting optical system or image transmitting means.

These images are equimultiply transmitted rearward by this relay opticalsystem 22 and finally the same images 10 a and 10 b as the two images 7a and 7 b by the two objective optical systems 21 a and 21 b areseparately formed on a photoelectrically converting surface (imagetaking surface) of an image taking device 23 arranged within the grippedsection 12. For example, in FIG. 5, if the separating direction in thetwo objective optical systems 21 a and 21 b is a horizontal direction,two images 10 a and 10 b will be separately formed in the horizontaldirection on the image taking surface of the image taking device 23.

As shown in FIG. 5, the image taking device 23 has, for example, asquare image taking surface and is arranged so that the vertical orhorizontal direction of this image taking surface may coincide with thehorizontal direction in which the two objective optical systems 21 a and21 b are arranged as separated and the center of the image takingsurface may be on the optical axis of the relay optical system.

By the way, the light guide 18 inserted through the inserted section 1may be inserted through outside the relay optical system 22 (forexample, like a ring). As shown in FIG. 5, a part of the verticaldirection intersecting at right angles with the horizontal direction ofthe relay optical system 22 may be contained in an incised groove formedby incising in the axial direction a part of the vertical directionintersecting at right angles with the horizontal direction of the relayoptical system 22. (One incised groove is shown in FIG. 5 but twoincised grooves may be formed in the vertical direction.) When suchincised groove is formed, the part which does not in principlesubstantially contribute to image transmission will be deleted, theimage transmitting function will not be reduced, the illuminating lightwill be able to be transmitted and the inserted section 11 will be ableto be made small in the diameter.

As the effective sectioned area of the relay optical system can be madelarge, the eccentricity (the distance d between the optical axes) of thetwo objective optical systems 21 a and 21 b arranged as opposed to eachother eccentrically in the horizontal direction from the optical axis ofthis relay optical system 22 at the front end of this relay opticalsystem 22, that is, the parallax will be able to be made large and thestereo-inspecting function will be able to be improved. Further, thereis a function of reducing the superimposing (cross talk) of two images.

The gripped section can be fittably separated into the output section 24in which the image taking device 23 is built-in and the input section 25on its forward side. The input section 25 has an image taking opticalsystem (observing optical system) comprising the two objective opticalseries 21 a and 21 b and relay optical system 22.

By making the output section 24 separable, there is made a flexiblestructure wherein the failing image taking device 23 can be easilyrepaired or can be replaced with one high in the sensitivity or thenumber of pixels to improve the performance and an ocular adapter can beconnected to make stereo-inspection with the naked eyes. (The structureshown in the later described FIG. 19 may be adopted for the structure ofthe connecting part.)

The image taking device 23 is extended out of the rear end of the outputsection 24 and is connected with the CCU 4 through the signal cable 26and the image taking signal photoelectrically converted by the imagetaking device 23 is processed. The image signal processed by this CCU 4is further put into the scan converter 5, is converted to a video signaland is then put out to the color monitor 6. Two images corresponding tothe optical images formed by the two objective optical systems 21 a and21 b are alternately displayed in this color monitor 6. By observing theimages of the color monitor 6 with shutter spectacles 27, the operatorcan stereo-inspect the images.

FIG. 6 shows the formations of the image taking optical systems, thatis, the two objective optical systems 21 a and 21 b and relay opticalsystem in the stereoendoscope 2 of the first embodiment.

The images 7 a and 7 b having a parallax from each other are formed bythe plural (two in this embodiment) independent objective opticalsystems 21 a and 21 b arranged in the distal end section 19. Theseimages 7 a and 7 b separated from each other are transmitted by therelay optical system 22 as one image transmitting optical system.

As shown in FIG. 6, the objective optical systems 21 a and 21 b, forexample, the three relay lens systems 22 a, 22 b and 22 c forming therelay optical system 22 and the image taking device 23 having a functionof photoelectrically converting optical images are arranged in the ordermentioned from the object side. The two images 7 a and 7 b having aparallax are formed in the spatially separated positions (in this case,in the positions separated from each other in the horizontal direction)by the objective optical systems 21 a and 21 b of the same formationarranged in parallel as separated from each other by d (for example, d=4mm) of the distance between their optical axes.

The images 7 a and 7 b are equimultiply relayed by the relay lenssystems 22 a, 22 b and 22 c of the same formation arranged in series sothat the optical axes may coincide with each other. That is to say, theimages 7 a and 7 b formed on both left and right sides of the opticalaxis O of the relay optical system 22 (by the objective optical systems21 a and 21 b arranged eccentrically on the left and right from thisoptical axis O) respectively form images 8 a and 8 b respectively onboth right and left sides of this optical axis O in the rear sidepositions of the optical axis O by the relay lens system 22 a. Theseimages 8 a and 8 b respectively form images 9 a and 9 b on both left andright sides of this optical axis O in the rear side positions of theoptical axis O by the relay lens system 22 b. These images 9 a and 9 brespectively form images 10 a and 10 b on both right and left sides ofthis optical axis O in the rear side positions of the optical axis O bythe relay lens system 22 c.

In this position, the image taking surface of the image taking device 23is arranged and the images 10 a and 10 b are photoelectrically convertedand put out. A masking means is provided so that the two images 10 a and10 b on this image taking surface may not be superimposed. (As shown inthe later described FIG. 8, for example, a visual field diaphragm 30 maybe provided on the image forming surfaces of the objective opticalsystems 21 a and 21 b to limit the visual field. The invention is notlimited to this. (The visual field diaphragm may be provided, forexample, in the image forming position in the relay optical system 22.)

The optical axes O of the relay lens systems 22 a, 22 b and 22 c arerespectively eccentric by the same amount on the right and left from theoptical axes Oa and Ob of the objective optical systems 21 a and 21 b.The eccentricity can be selected in conformity with the desired parallaxmagnitude, that is, stereo-feel size and is d/2 (for example, d/2=2 mm)in this embodiment.

The number of relaying times is three times in this embodiment but canbe set multiply from one time to ten and several times depending on suchspecification as the brightness of the optical system.

By the way, in FIG. 6, the reference numerals 28 a and 28 b respectivelyrepresent the positions of the incident pupils of the left and rightobjective optical systems 21 a and 21 b and the left and right images 7a and 7 b are formed of the lights incident through the respectiveincident pupils 28 a and 28 b. The respective incident pupils 28 a and28 b are transmitted by the relay lens systems 22 a, 22 b and 22 cforming the relay optical system 22.

During the transmission by the relay lens systems 22 a, 22 b and 22 c,the two pupils may be horizontally displaced but the relay lens systems22 a, 22 b and 22 c had better be superimposed in order to be madesmall. Therefor, it is preferable that the two objective optical systems21 a and 21 b are respectively formed to be telecentric optical systems,that is, the projecting pupils are formed to be infinitely far.

By the way, the magnitude of the parallax, that is, the center distancebetween the left and right incident pupils 28 a and 28 b is determinedby the distance d between the optical axes Oa and Ob of the objectiveoptical systems 21 a and 21 b and is independent of the brightness ofthe optical system.

According to this embodiment, as the relay optical system 22 is madecommon, the trouble of adjusting the lenses can be more extremelyomitted than in the case that it is not made common (in the firstrelated art) and a favorable stereo-observation can be made.

Also, as can be judged from FIG. 5, as an image having a parallax can beobtained by arranging the two objective optical systems 21 a and 21 b asseparated from each other, the parallax can be made larger than in thecase of using a common objective optical system (in the second relatedart) and therefore the function of obtaining a stereo-feel can be madelarge. (The same stereo-feel as in the case that two optical systems arearranged as in the first related art can be obtained.)

Therefore, according to this embodiment, the common optical componentscan be made few, the adjusted parts can be made few, the cost can bemade low and the image having the same stereo-feel as in the case thattwo optical systems are arranged in the related art can be obtained.

As the two images 7 a and 7 b having a parallax are transmitted by therelay lens systems 22 a, 22 b and 22 c used in common with the axiallysymmetrical one, during the transmission, the qualities (themagnification, MTF, image position, chromatic aberration, coloring andthe like) of the two images will lag little during the transmission.

That is to say, even if the individual characteristics of the relay lenssystem 22 a and the others are dispersed by the production error, inthis embodiment, as the left and right images are transmitted by thecommon relay lens system 22 a and the others, the influence of theindividual dispersion will not be substantially received. Therefore, theleft and right images obtained by this embodiment will be images of agood quality having little lag.

In case an operation is made under the observation with thisstereoendoscope, a good picture quality and a sufficient stereo-feelwill be obtained, a picture image of an observation close to directlyobserving the affected part will be able to be realized and therefore anenvironment in which the operation is easy to make will be able to beprovided.

Also, in this embodiment, as the left and right images 7 a and 7 b areformed in the positions spatially separated by the objective opticalsystems 21 a and 21 b and are formed in the positions spatiallyseparated by the common relay optical system 22, therefore astereo-inspection will be able to be made with the image taking deviceor the like without using an image separating means newly spatiallyseparating the images.

Also, in this embodiment, the final images 10 a and 10 b by the relaylens system 22 c are taken by one image taking device 23. Therefore, theoutput section 24 is very simplified in the structure and a light weightstereoendoscope can be realized.

By the way, the image taking device 23 may be any of various solid stateimage taking devices (known generally by the names of CCD, PCD, CMD, AMIand SIT) and image taking tubes (known generally by the names ofSachicon, Busicon and HARP TUBE).

Also, the sensitivity may be improved by utilizing an image intensifieror the like.

The image taking device 23 may be a device for taking color images witha single plate or may take colored images with a formation as a 2-plateor 3-plate camera. Also, as shown in FIG. 6, the final images 10 a and10 b by the relay lens system 22 c are taken by the common image takingdevice 23 to reduce the cost and weight.

In order that a stereo-feel optimum to the desire or operation type ofthe operator may be obtained, the distance between the respectiveoptical axes of the two objective optical systems 21 a and 21 b may bemade variable so that the magnitude of the parallax may be variable.

In this case, in order that the distal end section 19 may be made small,the two objective optical systems 21 a and 21 b may be made movable tothe side opposite to each other in the horizontal direction vertical tothe optical axis O of the relay lens systems 22 a, 22 b and 22 c.However, in this case, when the objective optical systems 21 a and 21 bmove, the final images 10 a and 10 b will be also moved by the relaylens system 22 c and therefore, in case the image taking device 23 isfixed, the movement will be limited to be within the image taking range.

By the way, it has been explained that the image taking surface of theimage taking device 23 is square. However, a rectangular surface long inthe horizontal direction in which the objective optical systems 21 a and21 b are arranged as separated may be used. In this case, the imagetaking range in which the image having a parallax is obtained will beable to be substantially expanded.

By the way, in FIG. 5 is adopted a simultaneous illuminating and imagetaking system wherein a color image is taken by using the image takingdevice 23 in which such color separating filter as a mosaic filter isarranged under a white color light illumination. However, the inventionis not limited to this. A surface sequent image taking system wherein acolor image is taken by obtaining such color component image as of threeprimary colors by taking an image with an image taking device having nocolor separating filter under a surface sequent illumination in whichilluminating lights of such wavelength ranges as of red, green and blueare sequentially emitted on the object side will also do.

By the way, in the first embodiment, instead of connecting the outputsection to the input section 25, an ocular adapter 45′ shown in thelater described FIG. 16D is fitted so that the stereo-inspection may bemade with the naked eyes. In this case, it is preferable to set thenumber of relaying times by the relay optical system 22 at an evennumber of times so that the left and right images 7 a and 7 b by theobjective optical systems 21 a and 21 b may be respectively observedwith the left and right ocular lenses. (In FIG. 16D, the number ofrelaying times is four times.)

By the way, the lens data of the first embodiment are as in Table 1shown at last in the specification. FIG. 2 and others are collectivelyshown after FIG. 1. In Tables 1 to 14, r1, r2, . . . , represent radiiof curvatures of respective surfaces, d1, d2, . . . , represent surfacedistances, n1, n2, . . . , represent refractive indices of respectivelenses and ν1, ν2, . . . , represent Abbe numbers of respective lenses.

In the following, the second to ninth embodiments are modifications ofthe first embodiment and, the same as in the first embodiment, the imagehaving a parallax is formed in a position spatially separated by theobjective optical systems 21 a and 21 b.

FIG. 7 shows a structure near the final images 10 a and 10 b of therelay lens system 22 c of the image taking optical system in thestereoendoscope of the second embodiment of the present invention. Thefinal images 10 a and 10 b are respectively taken by the two imagetaking devices 23 a and 23 b. Signal lines (not illustrated) areconnected respectively to the two image taking devices 23 a and 23 b andare connected to a CCU partly different in the internal formation fromthe CCU 4 in FIG. 5. The others are of the same formation as of thestereoendoscope 2 of the first embodiment.

By the way, in the CCU processing signals for the two image takingdevices 23 a and 23 b, the same driving signal may be simultaneouslyapplied, for example, to the two image taking devices 23 a and 23 b, maybe simultaneously read out and may be memorized respectively in twoframe memories. The same driving signal may be applied alternatelyrespectively to the two image taking devices 23 a and 23 b and may beread out alternately and the image signal read out may be memorizedalternately in the two frame memories.

The image signal simultaneously or alternately memorized in the twoframe memories are alternately read out by the scan converter and arealternately displayed in the color monitor. The operator wears shutterspectacles 27 and can observe and stereo-inspect the image displayed inthe color monitor 6.

The stereoendoscope apparatus provided with this second embodiment canbe realized in substantially the same formation as of thestereoendoscope apparatus 1 in FIG. 5.

This second embodiment has an advantage that the image taking devices 23a and 23 b can be focused respectively independently. If they areprecisely adjusted, an image higher in the quality than in the case of acommon image taking device 23 will be able to be made.

Also, the parallax can be made variable the same as in the firstembodiment. However, this embodiment has an advantage that, when theleft and right image taking devices 23 a and 23 b are moved asoperatively connected with the movement of the objective optical systems21 a and 21 b, the movement will not be restricted to be within theimage taking range in the case of the common image taking device 23.

That is to say, in the first embodiment, as the image taking device 23is common, the moving range of the left and right images 10 a and 10 bis restricted to be within the image taking range. However, according tothe present embodiment, in case the final images 10 a and 10 b arefixed, when the movement deviates (separates) from the imaging range,the two image taking devices 23 a and 23 b will be moved horizontally asoperatively connected with the movement of the objective optical systems21 a and 21 b and the final images 10 a and 10 b will be able to bemaintained within the image taking range of the respective image takingdevices 23 a and 23 b.

Therefore, there is a merit that a stereo-endoscope in which an imagehaving a stereo-feel is obtained can be realized. The others have thesame effects as in the first embodiment. By the way, the lens data ofthe second embodiment are the same as of the first embodiment.

FIGS. 8 and 9 relate to the third embodiment of the present invention.FIG. 8 shows an image taking optical system in the third embodiment.FIG. 9 shows as magnified the arrangement of the image taking devices 23a and 23 b. In this embodiment, the two image taking devices 23 a and 23b are used the same as in the second embodiment and the light receivingsurfaces of the image taking devices 23 a and 23 b arranged notvertically to the optical axis O of the relay optical system 22 but asinclined from the vertical direction. In other words, in the centralpart of the light receiving surface of each of the image taking devices23 a and 23 b, the optical axis vertical to this light receiving surfaceis arranged not to be parallel with the optical axis O of the relayoptical system 22 but to make an angle larger than O.

That is to say, when the light receiving surface of each of the twoimage taking devices 23 a and 23 b is arranged as inclined in conformitywith the image surface curvature aberration 10 c generated by the relaylens systems 22 a, 22 b and 22 c and shown in FIG. 2, the deteriorationof the image by the curvature aberration will be controlled or reduced.

As the petzval of the relay lens systems 22 a, 22 b and 22 c ispositive, even if the image surface by the objective optical systems 21a and 21 b is flat, in the case of the transmission by the relay lenssystems 22 a, 22 b and 22 c, the image surface will bend on the curvedsurface with the concave surface directed to the objective side.

Therefore, with the image taking surface or light receiving surface leftto be arranged vertically to the optical axis of the relay lens systems22 a, 22 b and 22 c, a partial fog will be likely to be produced and itwill be difficult to keep all the Image taking surface focused.

Therefore, in the third embodiment, as shown in FIG. 9, the lightreceiving surface is arranged as inclined in conformity with the contactsurface of the curved image surface. In FIG. 9, the light receivingsurface is inclined by 25.332 degrees to the surface vertical to theoptical axis of the relay lens system 22 c.

According to this third embodiment, not only the effects of the secondembodiment are retained but also a picture image having little curvatureaberration is obtained. By the way, the lens data of the thirdembodiment are as in Table 2.

By the way, as the petzval sum of the relay lens systems 22 a, 22 b and22 c is a positive value, the petzval sum of the objective opticalsystems 21 a and 21 b may be made a negative value to control the imagesurface curvature aberration of the final images 10 a and 10 b havingpassed through the relay lens system 22 c.

FIGS. 10A and 10B are of modifications showing this manner.

As shown in FIG. 10A, the petzval sum of the objective optical systems21 a and 21 b is made a negative value to form images 7 a and 7 bbecoming concave on the rear side (the local radius of curvature of eachimage surface shall be represented by R). In case the image on the flatimage surface is transmitted by the relay lens systems 22 a, 22 b and 22c, the local radius of curvature of the image surface of the finalimages 23 a and 23 b is represented by R′ and, as shown in FIG. 10, thelight receiving surfaces of the image taking devices 23 a and 23 b arearranged on the contact surface of the curved surface of a localcurvature 1/R″=1/R−1/R″, the influence of the image surface curvatureaberration will be further controlled by this embodiment than by thethird embodiment.

By the way, in this case, 1/R−1/R″=0 or the absolute value of 1/R−1/R″may be made small.

FIG. 11 shows an image taking optical system in the fourth embodiment.The final images 10 a and 10 b of the relay lens system are relayed oncemore by adapter lens systems 32 a and 32 b forming an adapter opticalsystem to connect images 36 a and 36 b and these images 36 a and 36 bare taken respectively by image taking devices 33 a and 33 b.

The adapter lens systems 32 a and 32 b are formed respectively of mirrorparts 34 a and 34 b and lens parts 35 a and 35 b, a beam is parallelmoved outside by the mirror parts 34 a and 34 b (in this embodiment, thedisplacement L is 6 mm) and the lens parts 35 a and 35 b act to re-formthe final images 10 a and 10 b of the relay lens system at anymagnification.

The optical axis of each of the lens parts 35 a and 35 b is eccentric byd/2(2 mm) from the optical axis of the relay lens system 22 c except theparallel moved part by the mirror parts 34 a and 34 b.

In this embodiment, when the parallel moving distance in the mirrorsections 34 a and 34 b and the magnification in the lens sections 35 aand 35 b are properly set, images 36 a and 36 b optimum to any sizeimage taking devices 33 a and 33 b will be able to be obtained.

Also, as the image taking devices 33 a and 33 b larger in the size thanin the first and second embodiments can be used, those larger in thenumber of pixels in response to the size can be used and a favorablestereo-observed image high in the resolving degree can be obtained. Theothers have the same effects as in the second embodiment. The lens dataof this embodiment are as in Table 3.

FIG. 12 shows an image taking optical system in the fifth embodiment.This embodiment is an improvement of the fourth embodiment.

The images 36 a and 36 b are respectively formed by relaying furtheronce the final images 10 a and 10 b of the relay lens system with thecommon adapter optical system 32 formed of one lens system and are takenby the image taking devices 33 a and 33 b. The adapter optical system 32is formed of a lens system arranged so as to be of the same optical axisas of the relay lens systems 22 a, 22 b and 22 c, the final images 10 aand 10 b of the relay lens system are formed again at any magnificationand the image taking devices 33 a and 33 b are arranged in the imageforming positions.

In this embodiment, the formation can be made simpler by the part havingno mirror section within the adapter optical system 32 and has theoperations and effects of the fourth embodiment. That is to say, whenthe magnification of the adapter optical system 32 is optionally set,the images 36 a and 36 b optimum to the image taking devices 33 a and 33b of any size will be able to be obtained.

Also, in this embodiment, the same as in the third embodiment, the lightreceiving surface of each of the image taking devices 33 a and 33 b isinclined in conformity with the image surface curvature aberrationgenerated by the relay lens systems 22 a, 22 b and 22 c and adapteroptical system 32 to control the deterioration of the image. In FIG. 12,the light receiving surface is arranged as inclined by 11.902 degrees tothe surface vertical to the optical axis of the relay lens system 22 c.The lens data of this embodiment are as in Table 4.

FIG. 13 shows an image taking optical system in the sixth embodiment.

The final images 10 a and 10 b of the relay lens system are further oncerelayed by the adapter lens systems 32 a and 32 b forming the adapteroptical system 32 and are taken by the image taking devices 33 a and 33b. The adapter optical system 32 is formed of the two inclined adapterlens systems 32 a and 32 b of the same formation. One lens system 32 band the image taking device 33 b are parallel eccentric by d/2(=2 mm)from the optical axis of the relay lens system 22 c and are theninclined by 10.076 degrees with the point at which the optical axis ofthe lens system 32 b intersects with the final image 10 b of the relaylens system 22 c as a center. The lens system 32 a illustrated by thetwo-point chain lines is also arranged as inclined the same on theopposite side of the optical axis of the relay lens system 22 c.

In this embodiment, too, the same as in the fifth embodiment, no mirrorsection is present and, by freely setting the magnification of theadapter optical system, the images 36 a and 36 b optimum to the imagetaking device of any size can be obtained. That is to say, thisembodiment has substantially the same effects as of the fifthembodiment. The lens data of this embodiment are as in Table 5.

FIG. 14 shows a main part of an image taking optical system in theseventh embodiment of the present invention.

The final images 10 a and 10 b of the relay lens system are further oncerelayed by the adapter optical system 32 and are formed in the samepositions and the common image taking device 33 is arranged in the imageforming position in the formation.

In the adapter optical system 32, the final images 10 a and 10 b of therelay lens system are led to the shutter means 37 e side through anoptical axis distance extending means comprising respectively lenses 37a and 37 b and prisms 37 c and 37 d and are led to the opposed lens 37 fand 37 g side so that, when one is shielding light, the other will bepassing light. A beam having passed through the lens 37 f arranged asopposed to one side of the shutter means 37 e passes through the prism37 h, half prism 37 i and lens 37 j and forms an image 36 a in theposition in which the image taking device 33 is arranged.

Also, a beam having passed through the lens 37 g arranged as opposed tothe other side of the shutter means 27 e passes through the opticaldevice 37 k, half prism 37 i and lens 37 j and forms an image 36 b inthe position in which the image taking device 33 is arranged.

In this embodiment, the relayed images 36 a and 36 b are formed in thesame position and are taken by one image taking device 33. The shuttermeans 37 e is arranged on the way of the adapter optical system 32 andalternately shields the beam so that two images may not besimultaneously formed by the image taking device 33.

This embodiment has an advantage that one image taking device 33 will doand the cost can be reduced. The others have the same effects as of thefourth embodiment.

FIGS. 15A and 15B show a formation of an objective optical system in theeighth embodiment of the present invention.

In this embodiment, an objective optical system is formed of perspectiveobjective optical systems 39 a and 39 b having a perspective front as avisual field.

In this embodiment, a beam incident from the diagonal front side isreflected by using reflecting prisms 40 a and 40 b as visual fielddirection changing means and is changed to be in a direction parallel tothe optical axis O of the relay optical system 22 (FIGS. 15A and 15Bshow only a part of the relay lens system 22 a). In this embodiment, thevisual field direction is 45 degrees with the lengthwise direction (theoptical axis direction of the relay optical system 22) of the insertedsection. The reflecting prisms 40 a and 40 b may be two separate bodiesor one integral body.

The rear side formation of the relay optical system 22 may be theformation of any of the first to sixth embodiments. This embodiment hasthe same effects as of the first to seventh embodiments except that thevisual field direction is different.

Otherwise than the eighth embodiment, the visual field direction can bevaried by varying the angles of the reflecting prisms 40 a and 40 b.Also, if the objective optical system parts are replaceably formed,various visual field directions, visual field angles and parallaxes willbe able to be obtained by replacing only the objective optical system.

FIGS. 16A to 16D show the ninth embodiment of the present invention anda unit formation in its first modification.

The stereoendoscope 41 of the ninth embodiment shown in FIG. 16Acomprises an objective optical system unit 42, relay optical system unit43, adapter optical system unit 44 and image taking device unit 45.

The objective optical system unit 42 has objective optical systems 21 aand 21 b of uniform optical characteristics built-in. The relay opticalsystem unit 43 has relay lens systems 22 a, 22 b, 22 c and 22 d of thesame formation built-in. The adapter optical system unit 45 has a commonadapter optical system 32 built-in. The image taking device unit 45 hasimage taking devices 33 a and 33 b of uniform characteristics built-in.

FIG. 16A as seen from the side is as in FIG. 16B. The objective opticalsystem unit 42 has a distal end side section of a light guide 18 and anilluminating lens 20 built-in. The relay optical system unit 43 has anintermediate section of the light guide 18 built-in. The adapter opticalsystem unit 44 has a rear end side section of the light guide 18built-in. A light guide mouthpiece 13 is provided.

Also, in this embodiment, the relay lens systems 22 a, 22 b, 22 c and 22d within the relay optical unit 43, for example, (for example, are cutoff in the lengthwise direction on the lower side to be in the directionvertical to the horizontal direction in which the objective opticalsystems 21 a and 21 b are arranged to secure a space to contain thelight guide 18 and) make the inserted section small in the diameter.Also, the adapter optical system 32 within the adapter optical systemunit 44 is cut off on the light guide mouthpiece 13 side.

In this embodiment, the objective optical system unit 42 is connected tothe distal end of the relay optical system unit 43, the distal end ofthe adapter optical system unit 44 is connected to the proximal end ofthe relay optical system unit 43 and the image taking device unit 45 isconnected to the proximal end of this adapter optical system unit 44 toform a stereoendoscope 41.

Therefore, by combining the respective units different in the opticalcharacteristics and image taking characteristic, stereoendoscopes ofdifferent characteristics can be simply realized. Therefore, thestereoendoscopes 41 of different characteristics can be provided so asto be selected by the users for their using objects.

In this embodiment, the connecting part of the proximal end of the relayoptical system unit 43 and the distal end of the adapter optical systemunit 44 corresponds to the border of the input section 25 and outputsection 24 shown in FIG. 5.

By the way, in FIGS. 16A and 16B, the part after the adapter opticalsystem unit 44 is made large in the diameter. However, as shown in FIG.16C, the proximal end side of the relay optical system unit 43 may bemade large in the diameter on the proximal end side, the proximal endside part of the light guide 18 may be built-in near this proximal endand the light guide mouth piece 13 may be provided there in thestructure.

In this first modification, the light guide 18 need not be built-in inthe adapter optical unit 44 and therefore the structure will be simple.

In this modification, the image taking device unit 45 may be fitteddirectly to the relay optical system unit 43 without using the adapteroptical system unit 44 in the structure. In such case, the formation ofthe second embodiment will be made. Further, in case one common imagetaking device is built-in as the image taking device unit 45, theformation of the first embodiment will be made.

This first modification is higher in the freedom of combination than theninth embodiment and can simply realize stereoendoscopes 41 different inthe characteristics. Also, as shown in FIG. 16D, when an ocular adapter45′ is connected to the proximal end of the relay optical system unit43, a stereoendoscope by which stereo-inspection can be made with thenaked eyes will be able to be formed.

The ocular adapter 45′ shown in FIG. 16D is of a structure whereby thefinal images by the relay optical system unit 43 can be magnified andobserved respectively through prisms and ocular lenses 45″a and 45″bfitted to an ocular window corresponding to the distance between botheyes of the operator so that the left and right images by the objectiveoptical systems 21 a and 21 b may be respectively stereo-inspectedthrough the left and right ocular lenses 45″a and 45″b.

By the way, in this case, as the final images are inverted images, theocular adapter 45′ is provided with lenses 45′a and 45′b as means formaking them upright to form upright images in front of the ocular lenses45″a and 45″b. Instead of providing the lenses 45′a and 45′b, the twoprisms for extending the distance between the optical axes may be madesuch prisms for inverting images as Porro prisms.

The ocular adapter for observation with the naked eyes may beconnectable to the relay optical system unit 43 in FIG. 16A in thestructure or may be connectable to the second to fourth modifications ofthe ninth embodiment shown in FIGS. 17A to 17C explained in thefollowing.

In the second modification shown in FIG. 17A, in FIG. 16A, the adapteroptical system 32 and the image taking devices 33 a and 33 b are formedof an adapter optical system image taking unit 46 as one unit.

In the third modification shown in FIG. 17B, in FIG. 17A, further, theobjective optical systems 21 a and 21 b and the relay optical system 22are formed of an objective optical system relay optical system unit 47as one unit. In the fourth modification shown in FIG. 17C, in FIG. 16A,the relay optical systems 22 and the adapter optical system 32 areformed of a relay optical system adapter optical system unit 48 as oneunit.

FIGS. 18A to 18E show more concrete formations of various units used inthe ninth embodiment and its modifications.

FIG. 18A shows an objective optical system unit 42 of a visual fieldangle of 70 degrees. FIG. 18B shows an objective optical system unit 42of a visual field angle of 40 degrees. When they are replaced and areconnected to a relay optical system unit 43, any desired visual fieldangle will be obtained.

A male screw is formed at the proximal end of the jacket tube of theobjective optical system unit 42 and can be removably connected by beingscrewed to a female screw at the distal end of the jacket tube of therelay optical system unit 43. A projection is provided at the proximalend of the jacket tube of the objective optical system unit 43 and canbe contacted with a level difference surface made by cutting off theinner peripheral surface on the distal end side of the jacket tube ofthe relay optical system unit 43 to determine the position in thelengthwise direction. By the way, both jacket tubes are of the sameoutside diameter so that, in case they are connected with each other, nolevel difference will be made on the inserted section.

Also, a positioning mark and screw hole are provided as peripheralpositioning means near the proximal end of the jacket tube of theobjective optical system unit 42. When this mark is made to meet apositioning mark at the distal end of the jacket tube of the relayoptical system unit 43, both screw holes will be able to be set tocommunicate with each other and will be able to be fixed with a screwnot illustrated.

By the way, the same connecting means or connecting mechanism as on theproximal end side of the jacket tube of the objective optical systemunit 42 is provided on the proximal end side of the jacket tube of therelay optical system unit 43 and can be removably connected to thedistal end of the jacket tube of the adapter optical system unit 44.

FIG. 18C shows an objective optical system unit 42 perspective in thevisual field direction of 45 degrees. In FIG. 18C, by replacing thereflecting prism 40, the objective optical system unit 42 perspective inany visual field direction can be formed. By the way, FIG. 18D showsFIG. 18C as seen from the rear end side and a pair of objective opticalsystems 39 a and 39 b arranged on the left and right.

FIG. 18E shows an objective optical system 42 in which the parallax isreduced and the optical axes of two objective optical systems 21 a and21 b are near to each other and the distance d′ between the optical axesis d′<d. In the case of this formation, the function of obtaining astereo-feel will reduce but, as the objective optical systems arearranged on the center axis side, a space for inserting them throughother internal organs or the like will be able to be secured, therefore,for example, the cross-sectioned area of the light guide will be able tobe made large, the illuminating light amount will be able to beincreased and a bright image will be obtained.

By the way, when the image taking device unit or the adapter opticalsystem unit is replaced, as required, in response to the optical axisdistance and visual field angle of the objective optical systems 21 aand 21 b, an optimum stereoendoscope conforming to the equivalent willbe able to be provided.

FIG. 19A shows a formation of a relay optical system unit 43. Theproximal end of this relay optical system 43 can be removably connectedto the distal end of the adapter optical system unit 44. Also, theproximal end of this adapter optical system unit 44 can be removablyconnected to the image taking unit 45.

As shown, for example, in FIG. 19B, the relay optical system unit may bethe relay optical system unit 43 in which the number of relaying timesis made twice. Further, a relay optical system unit in which the numberof relaying times is different depending on the inserted length insertedinto the body cavity or the like can be also used.

FIG. 19C shows a formation of an objective optical system relay opticalsystem unit 47 integrating an objective optical system and a relayoptical system. FIG. 19D is a modification of FIG. 19C and shows a unitin which the number of relaying times of the relay optical system ismade twice. Various numbers of relaying times of the relay opticalsystem can be prepared. A different length of the inserted section canbe selected as required.

In the following, the tenth to eighteenth embodiments are embodiments ofthe formation (b) in the above mentioned paragraph of the summary.Images having a parallax with each other are taken into the plural frontgroup optical systems of the objective optical systems arranged in thedistal end section of the endoscope and plural images in one rear groupoptical system are formed in substantially coinciding positions. Thesesubstantially superimposed images are transmitted by a common rear groupoptical system and a common image transmitting system coinciding withthis rear group optical system in the optical axis.

FIG. 20 shows an image taking optical system in the tenth embodiment.

An objective optical system 51 in which the object side opening part isseparated into two parts, relay lens systems 52 a, 52 b and 52 c, anadapter optical system 50 and image taking devices 53 a and 53 b arearranged in the order mentioned from the object side. The objectiveoptical system 51 is formed of front group optical systems (abbreviatedmerely as front groups) 54 a and 54 b of the same formation which areparallel arranged as separated by the distance d(=4 mm) between theoptical axes of each other and a rear group optical system (abbreviatedmerely as a rear group) 55 arranged to be of one same optical axis. Twoimages 56 a and 56 b having a parallax are formed in spatiallysubstantially coinciding positions.

The images 56 a and 56 b form a relay optical system and areequimultiply relayed by (for example, three) relay lens systems 52 a, 52b and 52 c of the same formation arranged in series so as to be of thesame optical axis with each other.

That is to say, by the relay lens system 52 a, the images 56 a and 56 bform images 57 a and 57 b with equal sizes in substantially the samepositions in the rear of this relay lens system 52 a. By the relay lenssystem 52 b, these images 57 a and 57 b form images 58 a and 58 b withequal sizes in substantially the same positions in the rear of thisrelay lens system 52 b. By the relay lens system 52 c, these images 58 aand 58 b form images 59 a and 59 b with equal sizes in substantially thesame positions in the rear of this relay lens system 52 c.

The rear group 55 of the objective optical system 51 and the opticalaxis of the relay lens systems 52 a, 52 b and 52 c are on the same axis.This optical axis and the optical axis of the front groups 54 a and 54 bare eccentric respectively on the left and right.

The eccentricity can be selected in conformity with a desired size, thatis, the size of the stereo-feel and is respectively d/2(=2 mm) in thisembodiment. An afocal beam may not be between the front groups 54 a and54 b and the rear group 55. However, for making small, this part may beof an afocal beam. An image formed by the objective optical system hadbetter be substantially superimposed.

For the picture angle of the ordinary relay system, the picture anglerequired by the endoscope is large. From the condition that, asdescribed above, the front groups 54 a and 54 b had better be nearlyafocal and from the condition that non-common parts had better be few,the front groups 54 a and 54 b had better be formed of two groups of aconcave group and convex group from the object side.

When the plural images having a parallax and transmitted by the relayoptical system are substantially superimposed, the relay optical systemwill be able to be made small in the diameter. Therefore, the projectedpupil of the objective optical system 51 may be made substantiallyinfinite. Therefore, the front side focal position of the rear group 55of the objective optical system 51 will be the pupil position. In orderthat the beam entering the front groups 54 a and 54 b from the objectmay be well transmitted to the rear group 55, it is preferable tocoincide with the projected pupil of the front groups 54 a and 54 b.Concretely, it is preferable that the final surfaces of the front groups54 a and 54 b are arranged on the image side rather than in the frontside focal position of the rear group 55.

In this embodiment, the number of relaying times is three times but canbe selected and set multiply to be usually one time to ten and severaltimes depending on such specifications as the length and diameter of theinserted section of the endoscope and the brightness and the like of theoptical system.

The magnitude of the parallax, that is, the center distance between theright and left incident pupils is determined by the optical axisdistance d between the front groups 54 a and 54 b of the objectiveoptical system 51 and is independent of the brightness of the opticalsystem.

According to this embodiment, the same as in the first embodiment, thetwo images 56 a and 56 b having a parallax are transmitted by oneaxially symmetrical relay optical system and therefore an error will belittle generated in the qualities (the magnification, MTF, imageposition, chromatic aberration, coloring and the like) of the two imagesbeing transmitted.

Non-common parts are less on the right and left of the objective opticalsystem 51 than in the first embodiment. Therefore, the trouble ofadjusting the lenses can be extremely omitted and a favorablestereo-observed image can be obtained.

Further, in this embodiment, as spatially substantially superimposedimages are transmitted by the relay optical system, when each of thefront groups 54 a and 54 b is formed of an elliptic lens system inwhich, for example, the horizontal direction is a short axis and thevertical direction is a long axis and the pupil is also made elliptic,the objective optical system and relay optical system will be able to bemade small in the diameter without deteriorating the parallax,brightness and the like. In this case, the inserted section will be ableto be made small in the diameter from the distal end to the proximal endside and the applied range in which the endoscope can be inserted andused will be able to be expanded. As the hole through which the insertedsection is inserted into the abdominal part may be small, the pain givento the patient will be able to be reduced. By the way, even in the otherembodiments, the objective optical system may be formed of an ellipticlens system.

In this embodiment, the final images 59 a and 59 b of the relay lenssystem 52 c are in substantially the same position and therefore must beseparated from each other by any means which is a pupil dividing imageforming means.

Therefor are required a means for forming an image of a pupiltransmitted by the relay optical system and a means for forming an imageof a partial beam of this pupil and forming an image by spatiallyseparating plural images having a parallax. Concretely, performing it isthe adapter optical system 50 formed of the pupil image forming lenssystem 61, mirror parts 62 a and 62 b and image forming lens systems 63a and 63 b arranged to be on the same optical axis as of the relay lenssystem 52 c.

The pupil image forming lens system 61 forms in spatially separatedpositions images of two pupils of the objective optical system 51transmitted by the relay lens systems 52 a, 52 b and 52 c. In the mirrorparts 62 a and 62 b, the beams of the two pupils are parallel movedoutside (in this embodiment, the movement is 6 mm) and the image forminglens systems 63 a and 63 b have an action of forming images 64 a and 64b respectively in the image taking devices 53 a and 53 b.

The optical axes of the image forming lens systems 63 a and 63 b areeccentric by d/2(=2 mm) from the optical axis of the relay lens system52 c except the parallel moved part by the mirror parts 62 a and 62 b.By the way, the mirror parts 62 a and 62 b and image forming lenssystems 63 a and 63 b are illustrated respectively only on one side.

Lest the right and left pupils should be finally superimposed, abrightness diaphragm 79 may be provided on the pupil surface (in thisembodiment, on the projecting pupil surface of the pupil image forminglens) in any of the pupil position and its conjugate position to limitthe beam.

In this embodiment, when the parallel moving distance in the mirrorparts 62 a and 62 b and the magnification of the adapter optical system50 are properly set, the images 64 a and 64 b optimum to the imagetaking devices 53 a and 53 b of any size will be able to be obtained.

As in FIG. 20, the parallel moving direction of the mirror parts 62 aand 62 b may be any direction within or vertical to the paper surface.When the focal distances of the image forming lens systems 63 a and 63 bare varied, the magnification will be able to be also varied.

In order to obtain the stereo-feel optimum to the operator's desire or asystem, the optical axis distances between each other of the two frontgroups 54 a and 54 b may be made variable so that the magnitude of theparallax may be variable. In this case, in order to make the distal endsection small, the two front groups 54 a and 54 b may be made movable inthe directions reverse to each other vertically to the optical axis ofthe relay optical system.

However, in this case, as the projected pupil of the objective opticalsystem is moved by the movement of the front groups 54 a and 54 b, itwill be necessary to make the effective diameter of each lens ratherlarge so that the beam may not be intercepted by the optical systemsfollowing the relay lens systems 52 a, 52 b and 52 c.

The others have the same operations and effects as of the firstembodiment. The lens data of this embodiment are as in Table 6.

The following eleventh to seventeenth embodiments are of the formationsmade by modifying the tenth embodiment. The images having a parallaxbetween each other are formed in spatially substantially coincidingpositions. All these objective optical systems 51 can be formed to beinterchangeable with the objective lenses of the pupil dividing typestereoendoscope of the related art.

FIG. 21 shows an image taking optical system in the eleventh embodimentof the present invention. Images 64 a and 64 b are formed by furtheronce relaying the final images 59 a and 59 b of the relay lens systemwith the adapter optical system 50 and are taken by the image takingdevices 53 a and 53 b.

The adapter optical system 50 is formed of a pupil image forming lenssystem 61 and image forming lens systems 63 a and 63 b arranged to be ofthe same optical axis as of the relay lens system 52 c. The optical axesof the image forming lens systems 63 a and 63 b are eccentric by 1.25d(=5 mm) from the optical axis of the relay lens system 22 c.

By the way, the image forming lens system is illustrated only on oneside. This embodiment is simpler by the part having no mirror partwithin the adapter optical system 50 than the tenth embodiment. The sameas in the tenth embodiment, when the magnification of the adapteroptical system 50 is freely set, the images 64 a and 64 b optimum to anyimage taking device will be able to be obtained. The distance betweenthe two pupils divided by the pupil image forming lens system 61 can bevaried by adjusting the focal distance of this pupil image forming lenssystem 61. The others have the same operations and effects as of thetenth embodiment.

The lens data of this embodiment are as in Table 7.

FIG. 22 shows an image taking optical system in the twelfth embodimentof the present invention. The front groups 54 a and 54 b of theobjective optical system 51 are formed of meniscus lenses 65 a and 65 bhaving a concave surface on the object side. In this embodiment, as thenon-common part of the right and left light paths is further less thanin the eleventh embodiment, the error will be less between the qualitiesof the two images.

The lens data of this embodiment are as in Table 8.

Further, when the meniscus lenses 65 a and 65 b are made an integrallymolded lens 65 as shown in FIGS. 23A to 23D, the error on the right andleft from the objective optical system 51 to the pupil image forminglens system 61 will be able to be reduced to a level where the errorwill not be a practical problem and the trouble of adjusting the lenseswill be well eliminated. The others have the same operations and effectsas of the eleventh embodiment.

By the way, of FIGS. 23A to 23D, FIG. 23A is a sectioned plan view, FIG.23B is a side view of FIG. 23A as seen in the side direction and FIGS.23C and 23D are a front view and back view respectively as seem from thefront side and back side.

FIG. 24 shows an image taking optical system in the thirteenthembodiment of the present invention. The final images 59 a and 59 b ofthe relay lens system are further once relayed by the adapter opticalsystem 50. As the adapter optical system 50 is of the same optical axisas of the relay lens system 52 c, the relayed images 64 a and 64 b willbe formed in substantially the same positions and will be taken by onecommon image taking device 53.

A shutter 66 is arranged between the pupil image forming lens system 61and image forming lens system 63 and alternately intercept the beam sothat two images may not be simultaneously formed in the image takingdevice 53.

This embodiment has an advantage that one image taking device 53 willdo. The others have the same effects as of the twelfth embodiment. Thelens data of this embodiment are as in Table 9.

FIG. 25 shows a main part of an image taking optical system in thefourteenth embodiment of the present invention. The same as in thethirteenth embodiment, as the adapter optical system 50 is of the sameoptical axis as of the relay lens system 52 c, the relayed images 64 aand 64 b will be formed in substantially the same positions and will betaken by one image taking device 53.

A lenticular lens 67 is arranged just before the light receiving surfaceof this image taking device 53 which is to be used in common. When theright and left images are formed at intervals of one row or one line bythe image taking device 53, the two images will be taken as separated.This embodiment has also an advantage that one image taking device 53will do. The others have the same effects as of the thirteenthembodiment. By the way, the lens data of this embodiment are the same asof the thirteenth embodiment.

FIGS. 26A and 26B show an objective optical system in the fifteenthembodiment of the present invention. In this embodiment, the visualfield direction is 30 degrees with the lengthwise direction of theendoscope (the optical axis direction of the relay lens). The reflectingprisms 68 a, 68 b and 69 a, 69 b forming the front groups 54 a and 54 bmay be respectively two separate bodies or one integral body.

FIG. 27 shows an objective optical system in a modification of thefifteenth embodiment of the present invention. The same as in thefifteenth embodiment, a perspective objective optical system 70 isformed. In this modification, the visual field direction is 70 degreeswith the lengthwise direction of the endoscope (the optical axisdirection of the relay lens). The reflecting prisms 68 a, 68 b and 69 a,69 b may be respectively two separate bodies or one integral body.

In the fifteenth embodiment and its modification, the visual fielddirection can be varied by varying the angles of the reflecting prisms68 a, 68 b and 69 a, 69 b. Therefore, when the front group part isformed to be interchangeable, various visual field directions or visualfield angles will be able to be obtained by interchanging only thisfront group. Needless to say, even when the entire objective opticalsystem is formed to be interchangeable, the same effects will beobtained. The others have the same effects as in the tenth embodiment.

FIG. 28 shows an image taking optical system in the sixteenth embodimentof the present invention. The same as in the fifteenth embodiment, inthis embodiment, the perspective objective optical system 70 is used. Inthis embodiment, the visual field direction is 45 degrees with thelengthwise direction of the endoscope (the optical axis direction of therelay lens). The reflecting prism 71 is integral on the right and left.

That is to say, in the illustrated tenth to fifteenth embodiments, theoptical system divided into two parts of the front groups 54 a and 54 bis adopted. However, in this embodiment, a reflecting prism 71 as acommon optical device is used to form a front group 54 functioning thesame as the two separated front groups 54 a and 54 b.

Negative lens systems 72 a and 72 b as negative power elements andpositive lens systems 73 a and 73 b as positive power elements to be apair forming the front group 54 on the left and right are formed asarranged eccentrically respectively on the left and right and arerotatable as illustrated. Therefore, the arranging direction of the twoincident pupils of the objective optical system, that is, the directionof the parallax (the direction of d in FIG. 28) can be varied and it isvery effective to stereo-observing an object in many directions.

In this embodiment, with the rotation of the negative lens systems 72 aand 72 b and positive lens systems 73 a and 73 b, the incident pupil ofthe pupil image forming lens system 61 will also rotate. In theembodiment shown in FIG. 28, the adapter optical system 50 shows anexample in case the same formation as of the eleventh embodiment isadopted. The image forming lens systems 63 a and 63 b and the imagetaking devices 53 a and 53 b will rotate so as to be synchronized toprevent the beam from being intercepted.

Even in this embodiment, when the angle of the reflecting prism 71 isvaried, the visual field direction will be able to be varied, when thecombination of the focal distances of the negative lens and positivelens is varied, the visual field angle will be able to be varied and,when the optical axis distance between the negative lens and positivelens on the left and right is varied, the magnitude of the parallax willbe able to be varied.

This embodiment can be applied to another adapter optical system.However, as mentioned above, with the rotation of the negative lenssystems 72 a and 72 b and positive lens systems 73 a and 73 b, theprojected pupil of the pupil image forming lens system 61 will alsorotate. Therefore, it is necessary to rotate such parts having left andright separate optical axes as, for example, the mirror parts 62 a and62 b, image forming lens systems 63 a and 63 b, image taking devices 53a and 53 b and the like as synchronized in the tenth embodiment in FIG.20. The others have the same effects as of the tenth embodiment.

FIG. 29 shows the seventeenth embodiment of the present inventionwherein the front group 54 including the negative lens systems 72 a and72 b and positive lens systems 73 a and 73 b is arranged on the objectside of the reflecting prism 71.

In this embodiment, as the rotating parts in the front group 54 part canbe concentrated in one place (in this case, on the object side of thereflecting prism 71) as compared with the sixteenth embodiment, theformation is simple. Also, FIG. 29 shows an example wherein is used theadapter optical system 50 of the same formation as of the thirteenthembodiment. The opening part of the shutter 66 rotates as synchronizedso that the beam may not be intercepted. At this time, such other partsas the image forming lens 63 and image taking device 53 may also rotatetogether with the shutter 66.

FIG. 30 shows unit formations of the eighteenth embodiment of thepresent invention. In FIG. 30A, the unit formation comprises the frontgroup unit 81 having the front groups 54 a and 54 b built-in, the reargroup—relay lens system—pupil image forming lens system unit 82 havingthe rear group 55, relay lens systems 52 a, 52 b and 52 c and pupilimage forming lens system 61 built-in, the image forming lens systemunit 83 having the image forming lens systems 63 a and 63 b built-in andthe image taking device unit 84 having the image taking devices 53 a and53 b built-in. By the way, the connecting part of the rear group—relaylens system—pupil image forming system unit 82 and the image forminglens system unit 83 corresponds to the border of the input section 25and output section 24 shown in FIG. 5.

FIG. 30B shows a formation of the image forming lens system—image takingdevice unit 85 wherein, in FIG. 30A, the image forming lens systems 63 aand 63 b and image taking devices 53 a and 53 b are made one unit.

FIG. 30C shows a formation in FIG. 30A of the objective optical systemunit 86 combining the front groups 54 a and 54 b in the front group unit81 and the rear group 55 in the rear group—relay lens system—pupil imageforming lens system unit 82, the relay lens system—pupil image forminglens system unit 87 having the relay lens systems 52 a, 52 b and 52 cand pupil image forming lens system 61 built-in and the image forminglens system—image taking device unit 85 the same as in FIG. 30B.

In FIG. 30D, the objective optical system (that is, the front groups 54a and 54 b and the rear group 55), relay lens systems 52 a, 52 b and 52c and pupil image forming lens system 61 are formed of the objectiveoptical system—relay lens system—pupil image forming system unit 88 andthe image forming lens system—image taking device unit 85 made one unit.

In FIG. 30E, the objective optical system and relay lens systems 52 a,52 b and 52 c are formed of the objective optical system—relay lenssystem unit 89 made one unit and the pupil image forming lens system 61,image forming lens systems 63 a and 63 b and image taking devices 53 aand 53 b are formed of the pupil image forming lens system—image forminglens system—image taking device unit 90 made one unit.

In FIG. 30F, the front group unit 81, rear group 55 and relay lenssystems 52 a, 52 b and 52 c are formed of the rear group—relay lenssystem unit 91 and pupil image forming lens system—image forming lenssystem—image taking device unit 90 made one unit.

In FIG. 30G, the relay lens systems 52 a, 52 b and 52 c are formed ofthe relay lens system unit 92, objective optical system unit 86 andpupil image forming lens system—image forming lens system—image takingdevice unit 90 made one unit. By the way, in FIGS. 30B to 30G, the lenssystem within each unit is shown with the reference numeral omitted.

Also, in FIGS. 30A to 30G, the ocular adapter 45′ shown in FIG. 16D maybe made connectable.

In FIG. 31, the front group unit 81 is more concretely explained. FIG.31A shows a front group unit 81 using a common front group 54. In caseit is fitted, a pupil dividing type stereoendoscope in the related artwill be able to be formed.

FIG. 31B shows the front group unit 81 of a visual field angle of 70degrees. FIG. 31C shows the front group unit 81 of a visual field angleof 40 degrees. When they are replaced, any desired visual field anglewill be obtained.

FIGS. 31D and 31E show a front group perspective unit 81 of a visualfield direction of 70 degrees. FIG. 31E is a view as seen from the rearof FIG. 31D. When the reflecting prism 71 is replaced, the front groupperspective unit 81 of any visual field direction will be able to beformed.

FIG. 31F shows the front group unit 81 in which the parallax is reducedand the optical axes of the front groups 54 a and 54 b are neared toeach other to make the distance d′ smaller than the other optical axisdistance d. In FIGS. 31A to 31F, if the beams from the front groups 54 aand 54 b are made substantially afocal beams, when the unit isdisplaced, a focus lag and image lag will be able to be controlled.

FIG. 32 shows a formation of the objective optical system unit.

FIG. 32A shows an objective optical system unit 86 comprising the frontgroup 54 and rear group 55 arranged to be of the same optical axis. Whenit is used, the pupil dividing type stereoendoscope in the related artwill be able to be formed. FIG. 32B shows an objective optical systemunit 86 having the front groups 54 a and 54 b of a visual field angle of70 degrees. FIG. 32C is of an objective optical system unit 86 havingthe front groups 54 a and 54 b of a visual field angle of 40 degrees.When these are replaced, any desired visual field angle will beobtained.

FIG. 32D is of a perspective objective optical system unit 86 of avisual field direction of 70 degrees. FIG. 32E is a front view of FIG.32D. When the reflecting prism 71 is replaced, a perspective objectiveoptical system unit of any visual field direction will be able to beformed. By the way, in FIG. 32E, the light guide is omitted.

FIG. 32F is of an objective optical system unit in which the parallax isreduced and the optical axes of the two front groups 54 a and 54 b areneared to each other so that the optical axis distance d′ may be smallerthan d, for example, in FIG. 32B and others.

FIG. 33 shows a formation of a unit including the rear group 55, relaylens systems 52 a and 52 b and pupil image forming lens system 61.

FIG. 33A is of the rear group—relay lens system—pupil image forming lenssystem unit 82 including the rear group 55, relay lens systems 52 a and52 b and pupil image forming lens system 61. FIG. 33B is of the relaylens system—pupil image forming lens system unit 87 including the relaylens systems 52 a and 52 b and pupil image forming lens system 61. FIG.33C is of the rear group—relay lens system unit 91 including the reargroup 55 and relay lens systems 52 a and 52 b. FIG. 33 is of the relaylens system unit 92 comprising the relay lens systems 52 a and 52 b.

Any number of relaying times of the relay lens system can be used. Asrequired, the inserted section different in the length can be selected.

The respective units in this eighteenth embodiment can be formed byadopting a part of the optical system of the tenth to seventeenthembodiment.

According to this eighteenth embodiment, the stereoendoscope of theformation adapted to the using object can be selected and used. Theothers have the effects of the tenth to seventeenth embodiments.

The following nineteenth and twentieth embodiments are embodimentswherein are used formations (a) in the means and operations for solvingthe above mentioned problems. When plural images taken in by anobjective optical system and having a parallax between each other aretransmitted by a common image transmitting optical system, are taken andare selectively displayed by a displaying means, the stereo-imagesoptimum to the observers will be provided.

FIG. 34A shows a formation of a stereoendoscope apparatus 101 providedwith the nineteenth embodiment of the present invention and an operationmade by using the stereoendoscope 102 of the nineteenth embodiment. FIG.34B shows an arrangement of an objective optical system 121 as seen fromthe distal end surface of the stereoendoscope 102.

This stereoendoscope apparatus 101 comprises a stereoendoscope 102having an image taking means for taking plural images having a parallaxbuilt-in, a CCU 103 processing signals for this imaging means, adistributor 104 connected to this CCU 103 and distributing videosignals, a color monitor 105 as plural displaying means displaying thevideo signals distributed by this distributor 104 and head mounteddisplays (abbreviated as HMD's) 106 and 107.

In FIG. 34A, a rigid inserted section 111 of the stereoendoscope 102 isinserted toward an affected part 114 from a hole 113 in an abdominalpart 112 of a patient. Two operators 115 and 116 respectively fit HMD'sto their head parts, observe the affected part 114 withstereo-inspection and treat the affected part 114 by using treatingtools 117 and 118. The treating tools 117 and 118 may be insertedthrough other holes or through channels in the stereoendoscope 102.

Also, another observer 119 (an assistant, nurse or spectator) observesthe same affected part with stereo-inspection by observing the colormonitor 105 with shutter spectacles 120 fitted.

The stereoendoscope 102 comprises an objective optical system 121, relayoptical system 122, adapter optical system 123 and image taking means124 in the order mentioned from the object side.

At least three images having a parallax between each other and formed bythe objective optical system 121 are transmitted by one (or plural)relay optical system 122 and are spatially (or timely) separated andformed by respective image taking devices forming the image taking means124. The electric signals of the respective images photoelectricallyconverted by the image taking means 124 are converted to video signalsby the CCU 103, are further divided into signals of any two images bythe distributor 104 and are displayed by the color monitor 105 and HMD's106 and 107 which are to be displaying means.

In this embodiment, when the so far shown various optical systems areused as combined with the objective optical system 121 and adapteroptical system 123, the stereo-image optimum to the respective operatorsand observers will be able to be provided very effectively.

When plural images are transmitted by one relay optical system built-inin one tubular inserted section 111, one hole 113 in the abdominal part112 will do and the burden on the patient will be able to be reduced.

As shown, for example, in FIG. 34B, the objective optical system 121 isformed of six objective lens systems 121 a to 121 d arranged in thepositions separated by a fixed distance from the center axis at an angleof 60 degrees from the center axis of the inserted section. The siximages by these objective lens systems 121 a to 121 f are taken, forexample, by six image taking devices forming the image taking means 124through the common relay optical system 122 and the adapter opticalsystem 123 formed, for example, of three adapter lens systems.

According to this formation, by selecting the image, for example, by theobjective lens systems 121 a and 121 d, a stereo-image large in theparallax can be obtained and, by selecting the image by the objectivelens systems 121 b and 121 e, a stereo-inspection large in the parallaxin the direction different by 60 degrees is possible. Further, byselecting the image by the objective lens systems 121 c and 121 f, astereo-inspection large in the parallax in the direction different by120 degrees is possible.

Further, by the combination in the above mentioned case, the parallaxwill become small. However, by selecting the image, for example, by theobjective lens systems 121 a and 121 c or the objective lens systems 121a and 121 e, an image having a stereo-feel in various directions can beobtained.

By the way, a remote display selecting means whereby the operator 115using the displaying device can remotely select the two imagesdistributed by the distributor 104 to the displaying device side of theHMD 106 or the like by a wireless remote controlling apparatus usinginfrared rays or ultrasonic waves may be provided.

An observing direction displaying means whereby, in case the image bythe objective lens systems (for example, 121 b and 121 e) in theparallax direction different from the parallax direction of a set ofobjective lens systems (for example, 121 a and 121 d) as a reference isselected, the parallax direction changing angle (in this case, 60degrees ) will be displayed within the displaying device so that thedirection in which the operator 115 or the like is observing may besimply found may be provided.

By the way, in this embodiment, n (at least three or plural) (in FIG.34, n=6) objective images are transmitted by one relay optical system122 but may be transmitted by n−i relay optical systems (here, i=1 ton−1).

FIG. 35 shows a formation of the stereoendoscope 131 of the twentiethembodiment of the present invention. FIG. 35A shows a general formationof the stereoendoscope 131. FIG. 35B shows an elevation as seen from thedistal end surface in FIG. 35A. FIG. 35C shows an arrangement of imagetaking devices as seen from the front surface side in FIG. 35A. In thisembodiment, too, plural sets of stereo-images can be obtained.

Plural front groups 133 (133 a to 133 f) forming an objective opticalsystem 132 arranged on the distal end side of the rigid inserted section111 take in images having a parallax between each other and an image 135is formed in substantially superimposed positions by one rear group 134to be common, is relayed some times by one relay optical system to becommon and becomes a final image 137.

This final image 137 is of plural images as superimposed. These imageshave their pupils spatially separated by a pupil image forming lenssystem 138 and, further, respective images 141 (141 a to 141 f) areformed on CCD's 140 (140 a to 140 f) by image forming lenses 139.

In this embodiment, six images having a parallax between each other canbe obtained. When two of them are selected and displayed, the imageshaving various stereo-feels and parallaxes will be able to bestereo-inspected. Also, plural persons can stereo-observe in separatedirections.

FIGS. 36A to 36F show distal end side formations of the stereoendoscopeof the twenty-first embodiment of the present invention. FIG. 36B is anelevation of FIG. 36A. FIG. 36C shows an optical system as seen from theside of FIG. 36A. FIG. 36D is an elevation of FIG. 36C. FIG. 36E showsFIG. 36C as bent. FIG. 36F is an elevation of FIG. 36E.

In this embodiment, the inserted section 152 can be bent on the distalend side.

A front group optical system 153, a rear group 154 a forming a relayoptical system 154 and a relay lens system 154 b are arranged from thedistal end side within the inserted section 152. The distal end section155 of the inserted section covering the objective optical system 153 isformed of a tubular frame having a curvable hose structure. The proximalside from the relay optical system 154 is formed of a rigid tubularframe.

Mirrors 158 and 159 are arranged between concave lenses 156 a and 156 bas of a front group and convex lenses 157 a and 157 b forming theobjective optical system 153 and are rotatable respectively around axes161 and 162.

When the mirrors 158 and 159 are rotated simultaneously with curvingfrom the straight seen state in FIG. 36C, the distal end section 155will be curved to be bent as in FIGS. 36E and 36F. According to thisembodiment, the observation can be made with the distal end sectionbent. The others have the same effects as of the first embodiment andothers.

FIG. 37 shows a formation on the distal end side of the stereoendoscopeof the twenty-second embodiment of the present invention. Thisembodiment is a combination of the twentieth embodiment wherein pluralsets of stereo-images can be obtained and the twenty-first embodimenthaving a bendable structure.

Usually, in an endoscope operation, the endoscope is not pierceddirectly into the abdominal part but is inserted through a tragacanth171. The thinner this tragacanth 171, the less the burden on thepatient. On the other hand, in case plural operators jointly operate, itwill be convenient that the observation can be made respectively in theseparate directions.

However, there is a limit to enlarging the parallax and the parallax cannot be made larger than the outside diameter of the distal end section.This embodiment can cope with such circumstances and makes it possibleto observe in separate directions.

In this embodiment, two bendable distal end sections 155 and 155′ areprovided forward of the relay optical system 154 and objective opticalsystems 153 and 153′ of the same structure as in the twentiethembodiment in FIG. 36 are contained within the respective distal endsections 155 and 155′. The same members as in FIG. 36 within the distalend section 155 shall bear the same reference numerals, the same membersas in FIG. 36 within the other distal end section 155′ shall bear thesame reference numerals fitted with ′ and their explanation shall beomitted.

According to this embodiment, when the distal end section is insertedwithin the tragacanth 171, it will be seen as straight as in FIG. 36C.When the distal end section comes out of the tragacanth 171, it will bebent as in FIG. 37A and plural observers will be able to observe inseparate directions through one thin relay optical system 154.

By the way, for example, in the first embodiment, each of the objectiveoptical systems 21 a and 21 b may be formed of an anamorphic opticalsystem wherein the image forming magnification in the horizontaldirection can be made smaller than the image forming magnification inthe vertical direction (intersecting at right angles with thishorizontal direction).

In the case of this formation, particularly, in case a common imagetaking device 23 is adopted, the two right and left images will be ableto be prevented from being superimposed and the right and left imagetaking ranges in the image taking device 23 will be able to besubstantially expanded.

In the function of transmitting images by the relay optical system 22,as the right and left images can be less intercepted (than in the caseof no anamorphic optical system), that much, the objective opticalsystems 21 a and 21 b will be able to be arranged as more separated fromeach other (with the optical axis distance d larger) and a picture imagehaving a higher stereo-feel will be able to be obtained.

In this case, in the CCU 4, the signal of extending the picture image inthe horizontal direction or compressing the picture image in thevertical direction may be processed.

By the way, the relay optical system 22 may be also formed of ananamorphic optical system. Even in the other embodiments, the objectiveoptical system, relay optical system and adapter optical system may beformed of anamorphic optical systems.

By the way, in the lens data of the respective embodiments, in case thesame lenses are paired in the objective optical system, adapter opticalsystem and the like, only the lens data of one of the pair will beshown. In the respective embodiments, the relay lens optical systemformed of a homogeneous bar-like lens is shown. However, even in case arefractive index distributing type lens is formed of suchnon-homogeneous rod as of a Shelphock (trade name) and is used for therelay optical system (image transmitting optical system), the presentinvention will be effective.

By the way, the embodiment wherein plural images having a parallax areformed in spatially separated positions by the objective optical systemand the embodiment wherein plural images having a parallax are formed inspatially substantially coinciding positions have been explained.However, the case of their intermediate functions, that is, the casethat plural images having a parallax are formed in spatially at leastpartly superimposed positions and the case that plural images having aparallax are formed in spatially at least partly separated positionsbelong to the present invention. Also, the case of applying an image byan objective optical system to the case that the image by the objectiveoptical system is transmitted by such image transmitting optical systemas the relay optical system belongs to the present invention.

As explained above, as the stereoendoscope in the fist to twenty-secondembodiments is provided with an objective optical system having pluralincident pupils formed in different positions and forming plural imageshaving a parallax between each other having passed through these pluralincident pupils and a common image transmitting optical systemtransmitting the plural images having a parallax between each other, theparallax will be able to be made large by the optical system, asufficient stereo-feel will be obtained, the parts of the light pathtransmitting plural images will be able to be made common by making theimage transmitting optical system common, the number of the parts willbe able to be reduced and the dispersion of plural images by productionerrors will be able to be extremely prevented.

When a stereoendoscope is formed by providing plural objective opticalsystems arranged in parallel, separating plural images having a parallaxand forming images and a common image transmitting optical systemtransmitting the plural images, the parallax will be able to be madelarge by the optical system, a sufficient stereo-feel will be obtained,the parts of the light path transmitting plural images will be able tobe made common by making the image transmitting optical system common,the number of the parts will be able to be reduced and the dispersion ofplural images by production errors will be able to be extremelyprevented. Further, as the images transmitted by the image transmittingoptical system are spatially separated, the stereo-inspection will bemade possible by the image taking means and ocular optical systemwithout using an image separating means.

Also, when a stereoendoscope is formed by providing plural front groupoptical systems, common rear group optical systems forming objectiveoptical systems forming plural images having a parallax in spatiallysubstantially coinciding positions and a common image transmittingoptical system transmitting the plural images, the parallax will be ableto be made large by the optical system, a sufficient stereo-feel will beobtained, the parts of the light path transmitting plural images will beable to be made common by making the image transmitting optical systemcommon, the number of the parts will be able to be reduced and thedispersion of plural images by production errors will be able to beextremely prevented. When a common rear group optical system is used inthe objective optical system part, many parts will be able to be madecommon and plural picture images less influenced by production errorsand high in the quality will be obtained.

Further, there is a stereo-inspectable endoscope in U.S. Pat. No.5,191,203 shown in FIG. 38A wherein an objective optical system 500 isformed of collimator lenses 501 and a pair of left and right imageforming lenses 502 a and 502 b arranged in the order mentioned from theobject side.

In the objective optical system of the stereoendoscope of this relatedart, there are the following three problems:

-   -   (1) When the picture angle is to be made large, the inward angle        will not be able to be made large and the stereo-feel will        reduce.

As in FIG. 38B, in case the picture angle is to be made large, it willbe necessary that the power arrangement of the collimator lenses 501will be negative and positive in the order from the object side. Whenthe power of the negative lens 503 on the object side is made large, thepicture angle will be able to be made large. However, in this case, thefocal distance fc of the collimator lenses 501 will become larger thanthe object distance s and the inward angle α will become small by thefollowing formula:α=2·arctan (d/2 fc)wherein d represents an optical axis distance between the two imageforming lenses 502 a and 502 b.

-   -   (2) A relative error between the left and right images is likely        to occur.

The relative error between the right and left images is produced mostlyin the parts of the left and right separate bodies by a surface shapeerror, surface distance error, eccentricity error or the like betweenright and left independent lens systems. In the prior example, the partsof the left and right separate bodies (the parts having left and rightseparate optical axes) correspond to the image forming lenses 502 a and502 b which are so many that an error is likely to occur. When arelative lag (focusing, eccentricity or the like) is produced betweenthe left and right images, the left and right images will become hard toresolve and fatigue will be caused.

-   -   (3) It is difficult to adjust the eccentricity error of the left        and right images.

In order to adjust the eccentricity error of the left and right images,the lens or CCD of the left and right separate body parts are adjusted.However, in the prior example, either is in a position through the otherpart (in this case, the collimator lens 501) from the distal end sectionof the endoscope and is difficult to adjust.

The twenty-third to twenty-fifth embodiments intended to provide astereoendoscope wherein the picture angle and stereo-feel (inward angle)can be set to be optimum, the error between the left and right images issmall and is easy to adjust and the fatigue is little for these threeproblems shall be explained.

In the stereoendoscope of these embodiments, there are an elongateinserted section, an objective optical system arranged within the distalend of the inserted section and an image taking means arranged withinthe inserted section and taking object images formed by the objectiveoptical system, the objective optical system is formed of two negativelenses and one coaxial positive lens arranged in parallel with eachother in the order mentioned from the object side, the inward angle isdetermined by the optical axis distance between the two negative lenses,therefore the picture angle and stereo-feel (inward angle) can be set tobe optimum, the error between the left and right images is small and iseasy to adjust and the fatigue feel can be reduced. In thestereoendoscope having an elongate inserted section,

In the twenty-third embodiment, the objective optical system is appliedto a so-called electronic scope having a CCD in the distal end part ofthe inserted section of the endoscope.

As shown in FIG. 39, a stereoendoscope apparatus 201 comprises astereoendoscope 202 of the twenty-third embodiment having an imagetaking optical system for stereo-inspection built-in, a light sourceapparatus 203 feeding an illuminating light to an illuminating lighttransmitting means transmitting the illuminating light and provided inthis stereoendoscope 202, a camera controlling unit (abbreviated as CCUhereinafter) processing signals for an image taking means built-in inthis stereoendoscope 202, a scan converter 205 converting to a videosignal the signal put out of this CCU 204, a color monitor 206displaying the video signal put out of this scan converter 205 andshutter spectacles 207 having a shutter function of stereo-perceivingthe picture image displayed by this color monitor 206.

The stereoendoscope 202 has an elongate inserted section 208 to beinserted into a body cavity or the like and a gripped section 209 to begripped by the operator and formed to be thick at the proximal end ofthis inserted section. This inserted section 208 is formed of acylindrical metallic hose high in the flexibility and a soft jacket tubemade of a metallic mesh and resin or the like. The distal end section216 of the inserted section 208 is formed of a cylindrical rigid jackettube made of such metal as stainless steel. An objective optical system218 and two image taking devices 220 a and 220 b (for example, CCD's)are enclosed in the distal end section 216. By the way, the entireinserted section may be formed of a rigid jacket tube the same as in thedistal end section.

This stereoendoscope has a light guide 215 as an illuminating lighttransmitting means transmitting the illuminating light fed from thelight source apparatus 203 and an illuminating optical system (notillustrated) emitting the transmitted illuminating light through anilluminating window the same as in the ordinary endoscope, obtains twoobserved images having a parallax so that the object illuminated by thisilluminating optical system may be stereo-inspected and has an observingoptical system comprising the optical system 218 and two image takingdevices 220 a and 220 b.

By the way, this embodiment explains an example wherein two imageshaving a parallax are formed by the image taking devices 220 a and 220 bhaving a photoelectrically converting function as an observing opticalsystem and is therefore called also an image taking optical system.

The gripped section 209 is provided with a light guide mouthpiece 210 towhich a light guide cable 211 is removably connected at one end. A lightguide connector 212 at the other end of the light guide cable 211 isremovably connected to the light source apparatus 203.

A lamp 213 generating a white illuminating light and a lens 214condensing this white light are arranged within the light sourceapparatus 203. The illuminating light condensed by this lens 214 isradiated on the end surface of the light guide connector 212, istransmitted by the light guide within the light guide cable 211, istransmitted from the light guide mouthpiece 210 to the light guide 215side within the stereoendoscope 202 and is fed.

The light guide 215 as an illuminating light transmitting means is bentwithin the gripped section 209 and is inserted through the insertedsection 208. This light guide 215 transmits the fed illuminating lightand omits the illuminating light forward from the distal end surfacefixed to the distal end section 216 of the inserted section 216.

An object (indicated by the arrow in FIG. 39) 217 illuminated by thisilluminating light has optical images (219 a and 219 b in FIG. 39)having a parallax between each other formed in image forming positionsby the objective optical system 218 fitted to an observing windowarranged adjacently to the illuminating window within the distal endsection. These images 219 a and 219 b are formed on the photoelectricconverting surfaces (image taking surfaces) of the image taking devices220 a and 220 b arranged the same within the distal end of the insertedsection.

As shown in FIG. 40, the objective optical system 218 is formed of leftand right separate negative lenses 221 a and 221 b and an axiallysymmetrical positive lens group 222 arranged in parallel with each otherin the order mentioned from the object side. The light having passedthrough a diaphragm opening 223 b of the light from the object forms animage on the image taking device 220 a and the light having passedthrough a diaphragm opening 223 a forms an image on the image takingdevice 220 b. By the way, a cover glass 240 made of parallel planeplates is arranged on the object side of the negative lenses 221 a and221 b.

Here, the lens data of the objective optical system 218 of thisembodiment are shown in Table 10.

In FIG. 39, the image taking devices 220 a and 220 b have, for example,square image taking surfaces. The vertical or horizontal direction ofthis image taking surface coincides with the horizontal direction inwhich the two diaphragm openings 223 a and 223 b are separated andarranged.

The image taking devices 220 a and 220 b are extended out and areconnected with the CCU 204 by the signal cable 224. The image takingsignal photoelectrically converted by the image taking devices 220 a and220 b is processed in the CCU 204. The image signal processed in thisCCU 4 is further put into a scan converter 205 and is converted to avideo signal. The video signal is put out in a color monitor 206 inwhich the picture images having a parallax between each other andseparately formed through the two diaphragm openings 223 a and 223 b arealternately displayed and the operator can observe and stereo-inspectthe picture images with the shutter spectacles.

FIG. 41 shows a power arrangement of the objective optical system 218 inthis embodiment. The inward angle a determining the magnitude of thestereo-feel is as follows from the optical axis distance d between thetwo negative lenses 221 a and 221 b and the object distance s:tan (α/2)=d/(2s).

That is to say, as shown in FIG. 41, the inward angle of the objectiveoptical system in this embodiment is determined by the optical axisdistance d between the two negative lenses and does not depend on thepicture angle. Further, as the left and right separate parts are onlythe negative lenses 221 a and 221 b, no relative error will be likely tobe produced. Therefore, there can be obtained the effects that:

-   -   (1) As the inward angle is determined by the optical axis        distance between the two negative lenses and the inward angle        and picture angle can be independently set, the picture angle        will be able to made large with the inward angle kept large.    -   (2) As the main cause of the relative error between the left and        right images is only the negative lens, the relative error        between the left and right images will be little.    -   (3) As the left and right separate parts for adjusting the error        between the left and right images are on the distal end side of        the endoscope, they will be easy to adjust.

FIG. 42 shows a frame structure of the distal end section 216 of thestereoendoscope 202 in this embodiment. The frame structure comprises aninner tube 225 holding lenses and a CCD and an outer tube 226 enclosingthe inner tube 225, an illuminating light guide and forceps channel notillustrated.

In the objective optical system of the prior example in FIG. 38A, as theleft and right separate bodies for adjusting the eccentricity of theleft and right images are in the positions through the collimator lensfrom the distal end within the inner tube, when they are to be adjusted,adjusting grooves, screws and adjusting spaces will have to be preparedin the inner tube and the inner tube will not be able to be made theinner tube 25 of such simple structure as in FIG. 42 and will be largein the outside diameter.

On the other hand, in this embodiment, as the two negative lenses 221 aand 221 b which are the left and right separate parts to be adjusted areoutside the distal end of the inner tube 225, the positions of thenegative lenses 221 a and 221 b will be able to be simply adjustedwithout making the inner tube 225 have a special structure. The negativelenses 221 a and 221 b are adjusted in the position and are then bondedand fixed and the inner tube 225 is inserted into the outer tube 226 tocomplete the stereoendoscope.

The twenty-fourth embodiment shall be explained in the following withreference to FIG. 43. As the twenty-fourth embodiment is substantiallythe same as the twenty-third embodiment, only the different formationsshall be explained.

In the twenty-fourth embodiment, the objective optical system of thestereoendoscope according to the present invention is applied to aso-called rigid endoscope wherein an image is transmitted to theproximal side by an objective optical system 218 and transmittingoptical system 227 arranged in an inserted section consisting of acylindrical rigid jacket tube and is taken.

As shown in FIG. 43, images 219 a and 219 b formed by the objectiveoptical system 218 are relayed by relay lenses 227 a, 227 b and 227 cwhich are of a transmitting optical system 227 and are then formed onCCD's 229 a and 229 b by an image taking lens 228. All the other lensesthan the negative lenses 221 a and 221 b at the distal end are coaxial.The images, that is, pupils of the diaphragm openings 223 a and 223 bare transmitted respectively to positions 250, 251, 252 and 253. Theother formations, operations and effects are the same as of thetwenty-third embodiment.

Here, the lens data of the objective optical system 218 and transmittingoptical system 227 in this embodiment are shown in Table 11.

The image taking lens 228 in this embodiment is one coaxial lens systembut the two pupils are separated in the position 253. Therefore, as theimage forming lens of the image taking lens shown in the following,image forming lenses arranged in parallel with each other may be usedafter the pupil 253 to form images.

The twenty-fifth embodiment shall be explained in the following withreference to FIGS. 44 and 45. As this embodiment is substantially thesame as the twenty-fourth embodiment, only the different formationsshall be explained.

The twenty-fifth embodiment is an embodiment as applied to a rigidendoscope the same as the twenty-fourth embodiment.

In this embodiment, as shown in FIG. 44, the basic formation of theobjective optical system 218 is the same as in the twenty-fourthembodiment. However, the image 219 a formed of the light having passedthrough the diaphragm opening 223 b of the light from the object and theimage 219 b formed of the light having passed through the diaphragmopening 223 a are partly superimposed.

The images 219 a and 219 b formed by the objective optical system 218are relayed by the relay lenses 227 a and 227 b as shown in FIG. 45, arethen formed to be infinite by the pupil image forming lens 230 and areformed respectively on the CCD's 229 a and 229 b by a pair of left andright image forming lenses 231 a and 231 b. The images (pupils) of thediaphragm openings 223 a and 223 b are transmitted respectively to thepositions 254, 255 and 256. As the two pupils have been separated in theposition 256, the two partly superimposed images 233 a and 233 b relayedby the relay lenses 227 a and 227 b are formed as separated by the imageforming lenses 231 a and 231 b. The other formations, operations andeffects are the same as in the twenty-fourth embodiment.

Here, the lens data of the objective optical system 218 and transmittingoptical system 227 of this embodiment are shown in Table 12.

In the 25th embodiment, the left and right separate parts are presentnot only in the distal end section (the negative lenses 221 a and 221 b)but also within the image taking lens 232 (the image forming lenses 231a and 231 b). Therefore, when the negative lenses are not adjusted butthe image forming lenses are adjusted, the eccentricity error betweenthe left and right images will be able to be adjusted.

However, in case the stereoendoscope 202 is made removable between theinput section (until the transmitting optical system 227 or until thepupil image forming lens) and the output section (after the pupil imageforming lens 230 or after the image forming lenses 231 a and 231 b), itwill be necessary that the input section and output section will berespectively independently adjusted. Therefore, even in such adjustmentof the input section, the objective optical system of the presentinvention is very effective.

A plural visual field direction type endoscope after the 26th embodimentshall be explained in the following.

The endoscope apparatus 310 shown in FIG. 46 has an inserted section302, an endoscope 311 in which the visual field direction is changeablein the 26th embodiment, a camera 304, monitor 305 and light sourceapparatus 307.

An objective optical system having plural visual field directions and alight guide illuminating the respective visual field directions areincorporated in the distal end section 301 of the inserted section 302of the endoscope 311. The inserted section 302 is provided with a relaylens system which is an image and pupil transmitting optical systemfollowing the objective optical system. An ocular optical system isarranged in the proximal section 303 of the endoscope 311. The camera304 can be fitted in the rear of the ocular optical system. Here, theproximal section 303 of the endoscope 311 and the camera 304 are formedto be integral or removable. The object having had the image taken bythe camera 304 is displayed to be observable by the observer as anendoscope picture image finally in the monitor 305.

The illuminating light from the light source apparatus 307 passesthrough the light guide cable 306 and illuminates the respective visualfield directions through the proximal section 303, inserted section 302and distal end section 301.

The details of the optical system of the endoscope 311 shall beexplained in the following:

On the optical systems of the endoscope of the 26th embodiment, a pupildivision is utilized in the objective optical system and an ocularoptical system is formed.

The pupil dividing system is fundamentally formed of an optical systemhaving one optical axis but, in order to make a plural visual fielddirection type, a lens group corresponding to plural visual fielddirections is arranged in front of the optical system. The plural visualfield direction type optical system having adopted this pupil dividingsystem is formed of a front side lens group formed the same in pluralvisual field directions and arranged in the respective visual fielddirections, a prism for forming images in the plural visual fielddirections in the rear step of the front side lens group correspondingto the plural visual field directions, a brightness diaphragm havingplural openings arranged near pupils to make plural pupils and a rearside lens group forming one image of superimposed beams in the pluralvisual field directions in the order mentioned from the object side.

The inherent one beam of the optical system is divided near the pupil bythe brightness diaphragm 321 having two openings and shown in FIG. 37B.The beam passing through one opening of the brightness diaphragm 321 isstraight seen as it is and the beam passing through the other opening ofthe brightness diaphragm 321 is perspectively seen in the visual fielddirection by the prism. Here, the two images in the visual fielddirection are formed as superimposed on the image surface.

The formation of the optical system relating to this embodiment shall beexplained concretely with reference to FIG. 47A. The optical systemshown in FIG. 47A comprises an objective optical system 322, a set ofrelay lens system 323 as a transmitting optical system and an ocularoptical system 324.

The objective optical system 322 has a front side lens group 329 acomprising two objective lenses 325 and 326 arranged in the positionsnearest to the object and directed respectively in the straight seendirection and side seen direction, a first prism 327 making the beamfrom the two objective lenses 325 and 326 incident on differentsurfaces, a second prism 328 making the beam from the first prism 327incident on the same surface and a brightness diaphragm 321 for dividingthe pupil into plural pupils in response to the visual field directionand has a rear side lens group 329 b for converging the beam from thepupils and forming the object image arranged in the rear of this frontside lens group 329 a. In the drawing, the one-point chain linesrepresent the optical axes of the respective visual field directions.

The image in the straight seen direction in this optical system isformed as follows. The rays having passed through the straight seeingobjective lens 326 pass through the surface 331 of the first prism 327to the joint surface 332. The joint surface 332 on the first prism side327 is black-painted so as to pass no others than the rays effective toprevent detrimental flares and is made a flare diaphragm. As the firstand second prisms 327 and 328 are made of the same glass material, theirrefractive indices are equal and the rays pass through the surface 332without being refracted, Then an image I1 having the lower side of thebrightness diaphragm 321 as a pupil surface and having the optical axisof this rear side lens group 329 b as a center axis by the rear sidelens group 329 b is formed.

On the other hand, the image in the perspectively seen direction isformed as follows. The rays having passed through the perspectivelyseeing objective lens 325 pass through the surface 333 of the firstprism 327 to the joint surface 332. At this time, the rays forming theimage in the perspectively seen direction proceed straight through thejoint surface without being refracted the same as the straight seenrays.

The joint surface 332 on the first prism side 327 is made a flarediaphragm passing no others than the rays effective to preventdetrimental flares. As the optical axis in the straight seen directionand the optical axis in the perspectively seen direction intersect witheach other on the joint surface, the same flare diaphragm willeffectively function on the rays in both directions. The straightproceeding rays in the perspectively seen direction are reflected by themirror-processed surface 334 and go again to the surface 332 on thesecond prism 328 side.

The surface 332 on the second prism 328 side is mirror-processed in therange of not intercepting the straight seen rays and perspectively seenrays separated by the pupil division and in the range of covering thereflected perspectively seen rays reflected by the surface 334.Therefore, the rays in the perspectively seen direction reflected by thesurface 334 without being perceived pass on the upper side of thebrightness diaphragm 321 and are made the image I1 having the opticalaxis of the rear side lens group 329 b as a center axis by this rearside lens group 329 the same as the straight seen rays and the image isformed.

The images I1 in the plural visual field directions made by theobjective optical system 322 and the pupil P1 are transmitted in theocular optical system direction by the relay lens system 323. In thedrawing, the reference numeral P2 represents plural pupils correspondingto the respective visual field directions transmitted by the relay lens.An image I2 is formed between the relay lens system 323 and ocularoptical system 324. Plural pupils P3 corresponding to the respectivevisual field directions are obtained through the ocular optical system324.

When the observer moves the position of his pupil to the position of thepupil transmitted in the visual field direction he wants to observe, hewill be able to select the visual field direction.

In this embodiment, the objective optical system is originally designedas a coaxial optical system but not as an eccentric optical system andis formed to be bent with a prism for a pupil in a different visualfield direction. That is to say, the optical axis of the objective lens326 is on the extended line of the optical axis of the rear side lensgroup 329 b through the joint surface 332 and the optical axis of theobjective lens 325 is on the extended line of the optical axis of therear side lens group 329 b reflected on the joint surface 332 andfurther reflected on the reflecting surface 334. Therefore, between theoptical system comprising two negative lenses and a prism and theoptical system in the rear of it, even if the beam is not afocal, twoimages superimposed before the relay system will be able to be formed.

In this embodiment, as the pupil division is utilized and originally oneoptical system is used, with a formation of few lenses, a high picturequality will be obtained, if the means for determining plural pupils isin a position conjugate with the pupil position of the objective opticalsystem, it may be the position of the pupil P2 of the relay system 323or any other part and, as the objective system and transmitting opticalsystem have no visual field direction switching apparatus, the structurewill be simple and the assemblability will be high.

An example of designing an actual objective optical system is shown inFIG. 48 and its numerical value data are mentioned in Table 13. By theway, in the formation shown in FIG. 48, the part shown as the rear sidelens group 329 b in FIG. 47A is formed of a lens 329″ jointed to a prismand three jointed lenses 329′.

In this embodiment, as the formed image is one, the following effectswill be able to be obtained.

That is to say, as the objective optical system of the plural visualfield direction type endoscope has plural visual field directions,plural pupils corresponding at 1 to 1 to the visual field directions andone image, the one image is a superimposition of images in plural visualfield directions, the optical axis of plural visual field directionscoincides with the optical axis of the transmitting system in theposition of the image and, on the way of the transmission in thetransmitting optical system after the image, one image and plural pupilswill be transmitted without being intercepted.

Therefore, in this embodiment, after the transmitting optical system,the visual field direction can be selected and no movable part isrequired in the objective optical system and transmitting optical systemfor selecting the visual field direction. Further, in this embodiment,as the objective optical system and the like have no visual fielddirection switching apparatus, the structure will be simple and theassemblability will be high. Also, as no polarization is used, therewill be no deterioration of the image in the peripheral part by therotation in the polarizing direction.

These effects will be the same even in case the pupil dividing means isin the transmitting optical system or image forming optical system.

The 27th embodiment shall be explained in the following with referenceto FIGS. 49 to 54.

In the endoscope of this embodiment, an eccentric optical system isutilized for the objective optical system, an image forming opticalsystem and solid state image taking device are used instead of theocular optical system in the 26th embodiment and no optical visual fielddirection selecting means is provided.

FIG. 49A shows a formation of an optical system arranged within theendoscope of this embodiment.

The optical system of this embodiment comprises in the order mentionedfrom the distal end side an objective optical system 341, relay lenssystem 342, pupil image forming lens 343, such reflecting members 344 aand 344 b as a pupil separating optical member 344 c and mirror and twosolid state image taking devices 346 a and 346 b as image taking means.By the way, though only one relay lens system is shown, it is naturalthat plural relay lens systems may be used as required. The imageforming lenses 345 a and 345 b form the image forming optical system.

In the objective optical system 341, a front optical system 347comprising substantially afocal lens groups 347 a and 347 b independentof each other and having two straight seen and perspectively seen visualfield directions and pupils P11 corresponding to these visual fielddirections is arranged in the front group and a rear side lens system348 having a size capable of transmitting the beams from the pluralpupils P11 to the image without being intercepted and forming onesuperimposed image of the beams in the plural visual field directions isarranged in the rear group.

The relay lens system 342 forms the images of the pupils P11 as pupilsP12, forms the image I11 as an image I12 and transmits them to a pupilimage forming lens 343. The pupil image forming lens 343 transmits thepupils transmitted from the relay lens system 342 to the side of a pupilseparating optical member 344 c having plural reflecting surfaces. Thispupil separating optical member 344 c receives plural pupils P13 andseparates and delivers them in respectively different directions, thatis, to the reflecting members 344 a and 344 b.

The reflecting members 344 a and 344 b reflect the beams having passedthrough the separated respective pupils, that is, in the illustration,the two pupils corresponding to the optical system in the straight seendirection and the optical system in the perspectively seen directionrespectively toward the lens systems 345 a and 345 b. The lens systems345 a and 345 b form images corresponding to the respective pupils inthe solid state image taking devices 346 a and 346 b.

In this formation, first the rays in the respective visual fielddirections pass through two substantially afocal lens groups 347 a and347 b forming the front optical system 347, then the optical axes in therespective visual field directions are bent by the rear side lens system348 and the image I11 is formed on the optical axis of the rear sidelens system 348.

In this embodiment, substantially the same basic formation as realizethe perspective view made by the prisms 327 and 328 in the 26thembodiment is used. Here, the perspective view prism may be a 30° prismshown in the publications of Japanese Patent Applications Laid OpenNos.140313/1985, 91333/1975 and 108013/1990 or a 70° prism or 110° prismshown in the publication of Japanese Patent Application Laid OpenNo.87403/1984.

Also, the objective optical system 341 may be the front optical system347 c including the same prisms as the prisms 327 and 328 of the abovementioned embodiment as in FIG. 50, that is, may be a straight seeingand perspectively seeing optical system in common. Or the objectiveoptical system 341 may realize a perspective view by utilizingrefraction with a wedge prism 349 placed near the pupil P11 as in FIG.51. In this formation, the lens group to be used respectively in thestraight seen direction and the perspectively seen direction may besubstantially the same lens group different only in the length, theperspectively seeing lens group may be arranged as inclined to thestraight seeing lens group and the wedge prism 349 may be arranged inthe rear of it.

Or else, as shown in FIG. 54, the objective optical system 341 may havethree or more visual field directions if in a range that the image andpupil are not intercepted by the relay lens system arranged in the rear.In the illustrated example are shown the most distal end side lenses350, 351 and 352 forming respective lens groups respectively of 0 degree(straight seen), 30 degrees (perspectively seen) and 70 degrees(perspectively seen).

As shown in FIG. 49A, the beam from the objective optical system 341forms an image I12 in the rear of the relay lens system the same as inthe 26th embodiment by the relay lens system 342. Of the rays in therespective visual field directions forming the image I12 made in therear of the relay lens system 342, the beams of the two pupils differentin the visual field direction are respectively separated by the pupilseparating optical member 344 c arranged in the rear of the pupil imageforming lens 343.

This pupil separating optical member 344 c is, for example, a prismarranged near the pupil P13 transmitted by the relay lens system 342 andformed as an image by the pupil image forming lens 343. The separatedbeams in the respective visual field directions are reflectedrespectively by the reflecting members 344 a and 344 b and are formed asimages respectively on the image taking devices 346 a and 346 b throughthe lens systems 345 a and 345 b.

In this embodiment, by the pupil image forming lens 343 forming imagesof pupils, the optical axes in the respective visual field directionsare made substantially parallel with the optical axis of the relay lenssystem 342 and the object point is formed as an image to infinity. Bythe way, the image may be formed so as not to be superimposed on onesolid state image taking device.

According to this embodiment, images different in the visual fielddirection can be independently taken by plural solid state image takingdevices and the number of visual fields and the visual field directioncan be easily selected by the objective optical system. Without anoptical visual field direction switching means, images in all the visualfield directions are taken in and taken. As in the illustrated example,in the formation using plural solid state image taking devices, theoutputs of the respective image taking devices are selected by switchingthe switch and the signals are processed as determined and can bedisplayed.

In the formation utilizing one solid state image taking device, therespective images different in the visual field direction may beselected by a signal processing means connected to the later step. Thepicture image in only one visual field direction can be displayed in amonitor.

That is to say, in this embodiment, without moving the optical system orwithout optically switching the visual field direction, the visual fielddirection can be changed. Also, depending on the way of processing thesignal, plural images in the visual field direction can besimultaneously displayed in one or plural monitors.

An example of designing an objective optical system is shown in FIG. 52.Also, an example of designing an objective optical system and relay lenssystem as combined is shown in FIG. 53. In the drawings, the referencenumeral 354 represents an objective optical system and the referencenumeral 355 represents a relay lens system. The lens data are mentionedin Table 14.

By the way, the same as in the 26th embodiment, the diaphragmdetermining the pupil may be in the objective optical system, may be inthe pupil position in the conjugate relay lens system or may be in thepupil position near the pupil dividing optical member.

In FIG. 49B is shown a modification of the 27th embodiment. In thismodification, a pupil image P13 is formed as of dispersed beams orconverged beams by the pupil image forming lens 356 provided instead ofthe pupil image forming lens 343, afocal beams are then formed by thelens 357 making the beams parallel and further the beams are formed asimages by the image taking devices 346 a and 346 b through the imageforming lenses 345 a and 345 b. In this modification, a reflexing prismas a pupil dividing optical member is unnecessary. The diaphragm may bearranged above the pupil position P13 in the drawing, in the relay lenssystem or in the pupil position in the objective optical system. Theother same formations and operations as in the 27th embodiment shallbear the same reference numerals and shall not be explained here.

The 28th embodiment of the present invention shall be explained in thefollowing with reference to FIGS. 55 to 58B.

In the formation of the 28th embodiment, an image forming optical systemand a solid state image taking device are provided the same as in the27th embodiment and further an optical visual field direction switchingmeans is arranged.

The objective optical system in this embodiment may be the pupildividing system in the 26th embodiment or may be formed of thesubstantially afocal plural optical systems and rear optical systems inthe 27th embodiment. This embodiment is different from the abovementioned respective embodiments in the formation of the optical systemand the like arranged in the rear of the relay lens system arranged inthe rear of the objective optical system.

As shown in FIG. 55, the optical system in this embodiment comprises alens system 361 for making the light which was once formed as an imageby a relay lens system in the rear of the relay lens system notillustrated and then became dispersed beams in the respective visualfield directions parallel with the optical axis of the relay lens, apupil switching apparatus 362 as a selecting means switching the beamsin the respective visual field directions made parallel in response tothe respective pupils and arranged near the pupils to be formed asimages through the lens system 361 and an image forming lens system 363forming images of the rays selected by the pupil switching device 362 onthe solid state image taking device 364.

The rays in the respective visual field directions forming the image I21formed in the rear of the relay lens system are made parallel with theoptical axis of the relay lens system by the lens system 361. By theswitching apparatus 362 near the pupil position, the rays passingthrough the other images than in the visual field direction the observerwants to observe are intercepted. The intercepting means as a selectingmeans may be a mechanically moved shielding plate or may be a liquidcrystal shutter switch to be on/off.

The selecting means may be such image rotator 365 as in FIGS. 56A and56B to be moved to switch the visual field direction. The referencenumeral 366 represents an image forming lens system forming an image ofthe rays obtained by the image rotator 365 on the solid state imagetaking device. By the way, FIGS. 56A and 56B show that the visual fielddirection is switched by moving the image rotator 365.

Also, as shown in FIG. 57, the selecting means may be moved to theposition of the visual field direction wanted to be observed integrallywith the image forming lens system 365 and solid state image takingdevice 364 to switch the visual field direction. Only the image in theselected visual field direction is formed on the solid state imageforming device 364.

The effect of this embodiment is that the visual field direction can bechanged in a small space.

By the way, in case the pupil and image made by the objective opticalsystem are transmitted by the relay lens system and the pupil dividingmeans is arranged after the relay lens system, the brightness diaphragm321 can be omitted.

The formations of the 27th and 28th embodiments have an image takingmeans and may be applied to an outside fitted camera connectable to theocular optical system of the 26th embodiment. In this formation, thelens system 343 or 361 is replaced with the ocular optical system 324.

The optical system after the transmitting optical system combiningutilizing the pupil division in the objective optical system andutilizing the eccentric optical system can be selected either to havethe ocular optical system and optical visual field direction switchingmeans or to have none.

In the case of either utilizing the pupil division in the objectiveoptical system of the present invention or utilizing the eccentricoptical system, when the means of intercepting the other rays than inthe required visual field direction are provided near the pupils in therespective visual field directions, even if the transmitting opticalsystem is replaced with the solid state image taking device or imageguide, the visual field direction variable endoscope will be able to berealized.

In the formation shown in FIG. 58A, a pupil switching apparatus 368 isprovided near the pupil formed in the light path of the objectiveoptical system 370 consisting of the front side lens group which is thesame as the front side lens group 329 a of the 26th embodiment and therear side lens system 348 and a solid state image taking device 369 isarranged. The pupil switching apparatus 368 may be a liquid crystalshutter or the like.

Also, in the formation shown in FIG. 58B, an eccentric optical system371 including the same optical system as the front optical system 347 cshown in FIG. 50 is utilized.

FIG. 59A is a formation view of an optical system in the plural visualfield direction type endoscope in the 29th embodiment. FIG. 59B is aformation view of an objective optical system made partly common.

The objective optical system in the 29th embodiment is formed of plurallens groups provided for respective visual fields instead of theobjective optical system 322 so that plural images may be formed bythese lens groups. The other formations and operations which are thesame as in the 26th embodiment shall bear the same reference numeralsand shall not be explained here.

The objective optical system 373 shown in FIG. 59A is formed of plural(two in the illustrated example) independent lens groups. The relay lenssystem 323 and ocular optical system 324 are arranged in the rear of theobjective optical system 373. By the way, the relay lens system 323 andocular optical system may be replaced with an image forming opticalsystem and solid state image taking device.

The objective optical system 373 may be formed of an independent opticalsystem as in FIG. 59A and may have a part, that is, the prism on thedistal end side made common as in the objective optical system 373′shown in FIG. 59B.

The plural images I31 and I32 formed by the objective optical system aretransmitted rearward by the relay lens system 323 as a transmittingoptical system. In the formation having the ocular optical system 324,as in FIG. 59A, the observer can simultaneously see the respectivevisual field directions with the eye placed in the pupil position 374.

On the other hand, in the formation of the image forming optical systemand solid state image taking device, the plural images made in the rearof the relay lens system 323 are formed on one solid state image takingdevice by the image forming lens. The effect by this formation can betechnically comparatively easily realized by any optical system afterthe objective optical system and transmitting optical system.

By the way, in this embodiment, images may be formed on plural solidstate image taking devices with the image forming magnification madelarge and the solid state image taking devices placed in the positionscorresponding to the plural images.

The 30th embodiment shall be explained with reference to FIG. 60A. Asshown in FIG. 60A, in the optical system of this embodiment, an image isformed on the solid state image taking device 370 through the lenssystem 343 which is arranged in the rear of the relay lens system 342and whereby the light once formed as an image by the relay lens system342 and then made dispersed beams in the respective visual fielddirections is made parallel with the optical axes of the relay lenssystem 342 and optical systems arranged along two optical axes in therear of this lens system 343.

Equimultiple relay systems by the lens systems 371 and 372 are arrangedalong one optical axis of the two optical axes and an image is formed onthe solid state image taking device 370 by the lens system 372.

Also, equimultiple relay systems are arranged on the other optical axis.That is to say, the prism 373 for bending the optical axis is arrangednear the pupil formed through the lens system 374 and on the rear sideof this prism 373 are arranged the lens system 374, prism 375, lenssystem 376, prism 377, lens system 378 and mirror 379. The beam isreflected by this mirror 379 arranged at the point P of intersection ofthis optical system and the other optical axis with each other and formsan image on the solid state image taking device 370 through the lenssystem 372.

This mirror 379 is rotatable as illustrated. The visual field directioncan be selected by switching to either of the state A indicated by thesolid line and the state B indicated by the dotted line. The otherformations are the same components as are explained in FIG. 49A.

In the inserted section of the rigid endoscope to which this embodimentis applied, the distance between the two optical axes can not help beingso small as to be several millimeters due to the restriction of theoutside diameter. As the image is formed on one solid state image takingdevice 370 after the lens system 343, in case one optical system is usedthe same as in the relay lens system 342, the beam will diagonallyproject into the solid state image taking device 370 and a color shadingwill be generated. In order to prevent this phenomenon, in thisembodiment, one of the two optical axes is bent by the prisms 373, 375and 377 on the rear side of the lens system 343 as in FIG. 60A so thatthe beams having passed respectively through the two optical axes mayproject vertically onto the image taking surface of the solid stateimage taking device 370 and the generation of the color shading may becontrolled.

FIG. 60B shows a formation of a modification of FIG. 60A. The opticalsystem in FIG. 60A is formed of expanded lens systems 374′, 376′ and378′ expanding respectively the lens systems 374, 376 and 378 so thatthe image may be observed in a larger picture surface size with one ofthe optical systems having two visual field directions. When theformation is separated into the inserted section 380 and the cameraadapter section 381 rotatably fitted to this inserted section 380 andthe camera adapter section 381 is rotatably formed, the picture sizes inthe respective visual field directions will be able to be selectivelymade large.

FIG. 61A shows the 31st embodiment. In this embodiment, objectiveoptical systems 391 and 391′ to be a pair on the respective optical axesseparated by a distance D are provided in the distal end side of theinserted section 390 and the respective images by the optical objectivesystems 391 and 391′ are transmitted to the rear side respectively bythe relay optical systems 392 and 392′.

The image transmitted by the relay optical system 392 is formed on thesolid state image taking device 370 by the equimultiple relay opticalsystems comprising the lens systems 371 and 372 the same as in FIG. 60A.

Also, the image transmitted by the relay optical system 392′ is formedon the solid state image taking device 370 through the same relaysystems as in FIG. 60A, that is, the equimultiple relay systems by theprism 373, lens system 374, prism 375, lens system 376, prism 377, lenssystem 378, mirror 379 and lens system 372.

The same as in the embodiment in FIG. 60A, as a means of switching thetwo optical systems, a mirror 379 is provided at the point P at whichthe two optical axes intersect with each other. The visual fielddirection can be selected by this mirror 379.

In the modification shown in FIG. 61B, the lens systems 374, 376 and 378forming the relay systems in FIG. 61A are formed respectively of theexpanded lens systems 374′, 376′ and 378′ so that one optical system,that is, the objective optical system 391′ and relay optical system 392′of the two optical systems arranged within the inserted section 390 maybe made thinner, the outside diameter of the inserted section may bemade smaller and the insertability may be improved.

Also, when the formation is separated into the inserted section 390 andthe camera adapter section 393 rotatably fitted to the rear end of thisinserted section and the camera adapter section 393 is rotatably formed,the picture size will be able to be selectively varied.

By the way, the present invention is not limited to these embodimentsand modifications and any embodiment or modification formed by combiningparts of them belongs to the present invention.

TABLE 1 Lens data of the first embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.300  r3 = 2.4658  d3 = 0.563  n2 =1.883  ν2 = 40.8  r4 = 0.7855  d4 = 0.453  r5 = ∞  d5 = 0.400  n3 =1.8061  ν3 = 40.9  r6 = ∞(pupil)  d6 = 3.340  n4 = 1.8061  ν4 = 40.9  r7= −2.7844  d7 = 0.300  r8 = −4.5712  d8 = 0.400  n5 = 1.62004  ν5 = 36.3 r9 = 13.1850  d9 = 0.730  n6 = 1.788  ν6 = 47.4 r10 = −3.7741 d10 =0.300 r11 = 6.2003 d11 = 1.949  n7 = 1.60311  ν7 = 60.7 r12 = −1.6595d12 = 0.409  n8 = 1.84666  ν8 = 23.8 r13 = −2.4812 d13 = 0.306 r14 =−2.3688 d14 = 0.400  n9 = 1.78472  ν9 = 25.7 r15 = −82.9824 d15 = 0.400n10 = 1.6968 ν10 = 55.5 r16 = −7.6931 d16 = 7.500 r17 = 17.7721 d17 =38.862 n11 = 1.51633 ν11 = 64.1 r18 = −8.3001 d18 = 6.881 n12 = 1.85026ν12 = 32.3 r19 = −24.9616 d19 = 0.941 r20 = 36.2005 d20 = 1.000 n13 =1.8061 ν13 = 40.9 r21 = ∞ d21 = 10.265 n14 = 1.51633 ν14 = 64.1 r22 = ∞d22 = 1.000 n15 = 1.8061 ν15 = 40.9 r23 = −36.2005 d23 = 0.914 r24 =24.9616 d24 = 6.881 n16 = 1.85026 ν16 = 32.3 r25 = 8.3001 d25 = 38.862n17 = 1.51633 ν17 = 64.1 r26 = −17.7721 d26 = 10.000 r27 = 17.7721 d27 =38.862 n18 = 1.51633 ν18 = 64.1 r28 = −8.3001 d28 = 6.881 n19 = 1.85026ν19 = 32.3 r29 = −24.9616 d29 = 0.914 r30 = 36.2005 d30 = 1.000 n20 =1.8061 ν20 = 40.9 r31 = ∞ d31 = 10.265 n21 = 1.51633 ν21 = 64.1 r32 = ∞d32 = 1.000 n22 = 1.8061 ν22 = 40.9 r33 = −36.2005 d33 = 0.914 r34 =24.9616 d34 = 6.881 n23 = 1.85026 ν23 = 32.3 r35 = 8.3001 d35 = 38.862n24 = 1.51633 ν24 = 64.1 r36 = −17.7721 d36 = 10.000 r37 = 17.7721 d37 =38.862 n25 = 1.51633 ν25 = 64.1 r38 = −8.3001 d38 = 6.881 n26 = 1.85026ν26 = 32.3 r39 = −24.9616 d39 = 0.914 r40 = 36.2005 d40 = 1.000 n27 =1.8061 ν27 = 40.9 r41 = ∞ d41 = 10.265 n28 = 1.51633 ν28 = 64.1 r42 = ∞d42 = 1.000 n29 = 1.8061 ν29 = 40.9 r43 = −36.2005 d43 = 0.914 r44 =24.9616 d44 = 6.881 n30 = 1.85026 ν30 = 32.3 r45 = 8.3001 d45 = 38.862n31 = 1.51633 ν31 = 64.1 r46 = −17.7721 d46 = 5.000 r47 = ∞(imageposition)

TABLE 2 Lens data of the third embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.300  r3 = 3.8772  d3 = 1.527  n2 =1.883  ν2 = 40.8  r4 = 0.7999  d4 = 0.449  r5 = ∞  d5 = 0.400  n3 =1.8061  ν3 = 40.9  r6 = ∞ (pupil)  d6 = 2.774  n4 = 1.8061  ν4 = 40.9 r7 = −2.6393  d7 = 0.300  r8 = −4.4440  d8 = 0.400  n5 = 1.62004  ν5 =36.3  r9 = 13.0243  d9 = 0.643  n6 = 1.788  ν6 = 47.4 r10 = −3.4953 d10= 0.300 r11 = 6.6459 d11 = 1.858  n7 = 1.60311  ν7 = 60.7 r12 = −1.6646d12 = 0.416  n8 = 1.84666  ν8 = 23.8 r13 = −2.4857 d13 = 0.300 r14 =−2.4171 d14 = 0.400  n9 = 1.78472  ν9 = 25.7 r15 = −5.1842 d15 = 0.400n10 = 1.6968 ν10 = 55.5 r16 = −5.8028 d16 = 7.500 r17 = 17.0269 d17 =39.876 n11 = 1.5l633 ν11 = 64.1 r18 = −9.1442 d18 = 6.480 n12 = 1.85026ν12 = 32.3 r19 = −25.2664 d19 = 0.300 r20 = 38.6357 d20 = 1.000 n13 =1.8061 ν13 = 40.9 r21 = ∞ d21 = 10.000 n14 = 1.51633 ν14 = 64.1 r22 = ∞d22 = 1.000 n15 = 1.8061 ν15 = 40.9 r23 = −38.6357 d23 = 0.300 r24 =25.2664 d24 = 6.480 n16 = 1.85026 ν16 = 32.3 r25 = 9.1442 d25 = 39.876n17 = 1.51633 ν17 = 64.1 r26 = −17.0269 d26 = 10.000 r27 = 17.0269 d27 =39.876 n18 = 1.51633 ν18 = 64.1 r28 = −9.1442 d28 = 6.480 n19 = 1.85026ν19 = 32.3 r29 = −25.2664 d29 = 0.300 r30 = 38.6357 d30 = 1.000 n20 =1.8061 ν20 = 40.9 r31 = ∞ d31 = 10.000 n21 = 1.51633 ν21 = 64.1 r32 = ∞d32 = 1.000 n22 = 1.8061 ν22 = 40.9 r33 = −38.6357 d33 = 0.300 r34 =25.2664 d34 = 6.480 n23 = 1.85026 ν23 = 32.3 r35 = 9.1442 d35 = 39.876n24 = 1.51633 ν24 = 64.1 r36 = −17.0269 d36 = 10.000 r37 = 17.0269 d37 =39.876 n25 = 1.51633 ν25 = 64.1 r38 = −9.1442 d38 = 6.480 n26 = 1.85026ν26 = 32.3 r39 = −25.2664 d39 = 0.300 r40 = 38.6357 d40 = 1.000 n27 =1.8061 ν27 = 40.9 r41 = ∞ d41 = 10.000 n28 = 1.51633 ν28 = 64.1 r42 = ∞d42 = 1.000 n29 = 1.8061 ν29 = 40.9 r43 = −38.6357 d43 = 0.300 r44 =25.2664 d44 = 6.480 n30 = 1.85026 ν30 = 32.3 r45 = 9.1442 d45 = 39.876n31 = 1.51633 ν31 = 64.1 r46 = −17.0269 d46 = 5.001 r47 = ∞ (imageposirion)

TABLE 3 Lens data of the forth embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.300  r3 = 2.6660  d3 = 1.000  n2 =1.883  ν2 = 40.8  r4 = 0.6568  d4 = 0.465  r5 = ∞  d5 = 0.400  n3 =1.883  ν3 = 40.8  r6 = ∞(pupil)  d6 = 2.938  n4 = 1.883  ν4 = 40.8  r7 =−2.9259  d7 = 0.300  r8 = −10.3818  d8 = 0.400  n5 = 1.62004  ν5 = 36.3 r9 = 15.1216  d9 = 0.562  n6 = 1.788  ν6 = 47.4 r10 = −4.9186 d10 =0.300 r11 = 6.1372 d11 = 1.797  n7 = 1.618  ν7 = 63.4 r12 = −1.8144 d12= 1.075  n8 = 1.84666  ν8 = 23.8 r13 = −2.6860 d13 = 0.300 r14 = −2.2723d14 = 0.615  n9 = 1.78472  ν9 = 25.7 r15 = −14.0716 d15 = 0.437 n10 =1.6968 ν10 = 55.5 r16 = −4.9749 d16 = 7.500 r17 = 18.4320 d17 = 37.230n11 = 1.51633 ν11 = 64.1 r18 = −8.3411 d18 = 6.671 n12 = 1.85026 ν12 =32.3 r19 = −24.0584 d19 = 0.300 r20 = 36.1875 d20 = 1.000 n13 = 1.8061ν13 = 40.9 r21 = ∞ d21 = 10.000 n14 = 1.51633 ν14 = 64.1 r22 = ∞ d22 =1.000 n15 = 1.8061 ν15 = 40.9 r23 = −36.1875 d23 = 0.300 r24 = 24.0584d24 = 6.671 n16 = 1.85026 ν16 = 32.3 r25 = 8.3411 d25 = 37.230 n17 =1.51633 ν17 = 64.1 r26 = −18.4320 d26 = 10.000 r27 = 18.4320 d27 =37.230 n18 = 1.51633 ν18 = 64.1 r28 = −8.3411 d28 = 6.671 n19 = 1.85026ν19 = 32.3 r29 = −24.0584 d29 = 0.300 r30 = 36.1875 d30 = 1.000 n20 =1.8061 ν20 = 40.9 r31 = ∞ d31 = 10.000 n21 = 1.51633 ν21 = 64.1 r32 = ∞d32 = 1.000 n22 = 1.8061 ν22 = 40.9 r33 = −36.1875 d33 = 0.300 r34 =24.0584 d34 = 6.671 n23 = 1.85026 ν23 = 32.3 r35 = 8.3411 d35 = 37.230n24 = 1.51633 ν24 = 64.1 r36 = −18.4320 d36 = 10.000 r37 = 18.4320 d37 =37.230 n25 = 1.51633 ν25 = 64.1 r38 = −8.3411 d38 = 6.671 n26 = 1.85026ν26 = 32.3 r39 = −24.0584 d39 = 0.300 r40 = 36.1875 d40 = 1.000 n27 =1.8061 ν27 = 40.9 r41 = ∞ d41 = 10.000 n28 = 1.51633 ν28 = 64.1 r42 = ∞d42 = 1.000 n29 = 1.8061 ν29 = 40.9 r43 = −36.1875 d43 = 0.300 r44 =24.0584 d44 = 6.671 n30 = 1.85026 ν30 = 32.3 r45 = 8.3411 d45 = 37.230n31 = 1.51633 ν31 = 64.1 r46 = −18.4320 d46 = 5.000 r47 = ∞ d47 = 6.000(reflection plane) r48 = ∞ d48 = 9.000 (reflection plane) r49 = −15.7631d49 = 4.949 n32 = 1.816 ν32 = 46.6 r50 = −8.9021 d50 = 2.525 r51 =9.9691 d51 = 4.480 n33 = 1.72916 ν33 = 54.7 r52 = −16.7003 d52 = 2.578n34 = 1.7552 ν34 = 27.5 r53 = 4.2972 d53 = 3.722 r54 = 52.6411 d54 =1.000 n35 = 1.5927 ν35 = 35.3 r55 = 117.6536 d55 = 7.067 n36 = 1.618 ν36= 63.4 r56 = −77.9950 d56= 1.037 r57 = 8.7799 d57 = 7.000 n37 = 1.72916ν37 = 54.7 r58 = 13.9542 d58 = 49.995 r59 = ∞(image position)

TABLE 4 Lens data of the fifth embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 7l.8  r2 = ∞  d2 = 0.300  r3 = 2.8586  d3 = 1.000  n2 =1.883  ν2 = 40.8  r4 = 0.7279  d4 = 0.466  r5 = ∞  d5 = 0.400  n3 =1.883  ν3 = 40.8  r6 = ∞(pipul)  d6 = 2.216  n4 = 1.883  ν4 = 40.8  r7 =−2.9043  d7 = 0.300  r8 = −5.6042  d8 = 0.400  n5 = 1.62004  ν5 = 36.3 r9 = 5.6154  d9 = 0.888  n6 = 1.788  ν6 = 47.4 r10 = −3.6606 d10 =0.300 r11 = 7.1344 d11 = 1.764  n7 = 1.618  ν7 = 63.4 r12 = −1.7751 d12= 0.597  n8 = 1.84666  ν8 = 23.8 r13 = −2.5646 d13 = 0.302 r14 = −2.1629d14 = 0.400  n9 = 1.78472  ν9 = 25.7 r15 = −4.7832 d15 = 0.400 n10 =1.6968 ν10 = 55.5 r16 = −3.9862 d16 = 7.500 r17 = 18.1763 d17 = 37.730n11 = 1.51633 ν11 = 64.1 r18 = −8.5520 d18 = 6.670 n12 = 1.85026 ν12 =32.2 r19 = −23.4978 d19 = 0.300 r20 = 39.1240 d20 = 1.000 n13 = 1.8061ν13 = 40.9 r21 = ∞ d21 = 10.000 n14 = 1.51633 ν14 = 64.1 r22 = ∞ d22 =1.000 n15 = 1.8061 ν15 = 40.9 r23 = −39.1240 d23 = 0.300 r24 = 23.4978d24 = 6.670 n16 = 1.85026 ν16 = 32.2 r25 = 8.5520 d25 = 37.730 n17 =1.51633 ν17 = 64.1 r26 = −18.1763 d26 = 10.000 r27 = 18.1763 d27 =37.730 n18 = 1.51633 ν18 = 64.1 r28 = −8.5520 d28 = 6.670 n19 = 1.85026ν19 = 32.2 r29 = −23.4978 d29 = 0.300 r30 = 39.1240 d30 = 1.000 n20 =1.8061 ν20 = 40.9 r31 = ∞ d31 = 10.000 n21 = 1.51633 ν21 = 64.1 r32 = ∞d32 = 1.000 n22 = 1.8061 ν22 = 40.9 r33 = −39.1240 d33 = 0.300 r34 =23.4978 d34 = 6.670 n23 = 1.85026 ν23 = 32.2 r35 = 8.5520 d35 = 37.730n24 = 1.51633 ν24 = 64.1 r36 = −18.1763 d36 = 10.000 r37 = 18.1763 d37 =37.730 n25 = 1.51633 ν25 = 64.1 r38 = −8.5520 d38 = 6.670 n26 = 1.85026ν26 = 32.2 r39 = −23.4978 d39 = 0.300 r40 = 39.1240 d40 = 1.000 n27 =1.8061 ν27 = 40.9 r41 = ∞ d41 = 10.000 n28 = 1.51633 ν28 = 64.1 p42 = ∞d42 = 1.000 n29 = 1.8061 ν29 = 40.9 r43 = −39.1240 d43 = 0.300 r44 =23.4978 d44 = 6.670 n30 = 1.85026 ν30 = 32.2 r45 = 8.5520 d45 = 37.730n31 = 1.51633 ν31 = 64.1 r46 = −18.1763 d46 = 15.000 r47 = −15.9408 d47= 7.000 n32 = 1.816 ν32 = 46.6 r48 = −10.5614 d48 = 1.898 r49 = 20.0434d49 = 1.000 n33 = 1.72916 ν33 = 54.7 r50 = 11.2226 d50 = 1.852 n34 =1.7552 ν34 = 27.5 r51 = 8.3607 d51 = 6.099 r52 = −24.1926 d52 = 3.535n35 = 1.5927 ν35 = 35.3 r53 = 9.6335 d53 = 9.958 n36 = 1.618 ν36 = 63.4r54 = −27.0337 d54 = 0.300 r55 = 22.5105 d55 = 7.000 n37 = 1.72916 ν37 =54.7 r56 = 317.0029 d56 = 102.172 r57 = ∞(image position)

TABLE 5 Lens data of the sixth embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.300  r3 = 2.5311  d3 = 1.000  n2 =1.883  ν2 = 40.8  r4 = 0.6002  d4 = 0.483  r5 = ∞  d5 = 0.492  n3 =1.883  ν3 = 40.8  r6 = ∞(pupil)  d6 = 2.925  n4 = 1.883  ν4 = 40.8  r7 =−2.9244  d7 = 0.300  r8 = −20.1110  d8 = 0.500  n5 = 1.62004  ν5 = 36.3 r9 = 10.9637  d9 = 0.607  n6 = 1.788  ν6 = 47.4 r10 = −6.2777 d10 =0.300 r11 = 6.1192 d11 = 1.860  n7 = 1.618  ν7 = 63.4 r12 = −1.8981 d12= 0.810  n8 = 1.84666  ν8 = 23.8 r13 = −2.7109 d13 = 0.302 r14 = −2.2811d14 = 0.400  n9 = 1.78472  ν9 = 25.7 r15 = −13.8892 d15 = 1.289 n10 =1.6968 ν10 = 55.5 r16 = −5.4300 d16 = 7.500 r17 = 18.4228 d17 = 37.662n11 = 1.51633 ν11 = 64.1 r18 = −8.3677 d18 = 6.665 n12 = 1.85026 ν12 =32.3 r19 = −24.4094 d19 = 0.300 r20 = 35.7941 d20 = 1.000 n13 = 1.8061ν13 = 40.9 r21 = ∞ d21 = 10.000 n14 = 1.51633 ν14 = 64.1 r22 = ∞ d22 =1.000 n15 = 1.8061 ν15 = 40.9 r23 = −35.7941 d23 = 0.300 r24 = 24.4094d24 = 6.665 n16 = 1.85026 ν16 = 32.3 r25 = 8.3677 d25 = 37.662 n17 =1.51633 ν17 = 64.1 r26 = −18.4228 d26 = 10.000 r27 = 18.4228 d27 =37.662 n18 = 1.51633 ν18 = 64.1 r28 = −8.3677 d28 = 6.665 n19 = 1.85026ν19 = 32.3 r29 = −24.4094 d29 = 0.300 r30 = 35.7941 d30 = 1.000 n20 =1.8061 ν20 = 40.9 r31 = ∞ d31 = 10.000 n21 = 1.51633 ν21 = 64.1 r32 = ∞d32 = 1.000 n22 = 1.8061 ν22 = 40.9 r33 = −35.7941 d33 = 0.300 r34 =24.4094 d34 = 6.665 n23 = 1.85026 ν23 = 32.3 r35 = 8.3677 d35 = 37.662n24 = 1.51633 ν24 = 64.1 r36 = −18.4228 d36 = 10.000 r37 = 18.4228 d37 =37.662 n25 = 1.51633 ν25 = 64.1 r38 = −8.3677 d38 = 6.655 n26 = 1.85026ν26 = 32.3 r39 = −24.4094 d39 = 0.300 r40 = 35.7941 d40 = 1.000 n27 =1.8061 ν27 = 40.9 r41 = ∞ d41 = 10.000 n28 = 1.51633 ν28 = 64.1 r42 = ∞d42 = 1.000 n29 = 1.8061 ν29 = 40.9 r43 = −35.7941 d43 = 0.300 r44 =24.4094 d44 = 6.665 n30 = 1.85026 ν30 = 32.3 r45 = 8.3677 d45 = 37.662n31 = 1.51633 ν31 = 64.1 r46 = −18.4228 d46 = 5.000 r47 = ∞ d47 = 11.000r48 = −10.3813 d48 = 5.655 n32 = 1.816 ν32 = 46.6 r49 = −8.8890 d49 =0.483 r50 = 7.4696 d50 = 3.769 n33 = 1.72916 ν33 = 54.7 r51 = 181.6429d51 = 2.093 n34 = 1.7552 ν34 = 27.5 r52 = 4.4460 d52 = 3.047 r53 =−30.7603 d53 = 1.001 n35 = 1.5927 ν35 = 35.3 r54 = 41.5845 d54 = 1.706n36 = 1.618 ν36 = 63.4 r55 = −17.8259 d55 = 0.342 r56 = 7.9775 d56 =5.749 n37 = 1.72916 ν37 = 54.7 r57 = 12.6259 d57 = 39.986 r58 = ∞(imageposition)

TABLE 6 Lens data of the tenth embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.500  r3 = −15.1509  d3 = 0.500  n2 =1.883  ν2 = 40.8  r4 = 1.8541  d4 = 0.400  r5 = ∞  d5 = 1.471  n3 =1.8061  ν3 = 40.9  r6 = ∞(pupil)  d6 = 8.000  n4 = 1.8061  ν4 = 40.9  r7= −6.3400  d7 = 0.300  r8 = 29.8778  d8 = 6.980  n5 = 1.60311  ν5 = 60.7 r9 = −76.5455  d9 = 2.000 r10 = 11.8863 d10 = 12.000  n6 = 1.60311  ν6= 60.7 r11 = −14.2286 d11 = 1.000  n7 = 1.84666  ν7 = 23.8 r12 = 6.6719d12 = 1.327 r13 = 16.2399 d13 = 1.000  n8 = 1.84666  ν8 = 23.8 r14 =6.8781 d14 = 2.641  n9 = 1.60311  ν9 = 60.7 r15 = −16.3999 d15 = 0.300r16 = 9.6243 d16 = 2.045 n10 = 1.72916 ν10 = 54.7 r17 = 42.1473 d17 =12.000 r18 = 20.3224 d18 = 28.648 n11 = 1.51633 ν11 = 64.1 r19 = −9.1270d19 = 1.000 n12 = 1.85026 ν12 = 32.3 r20 = −17.5105 d20 = 0.300 r21 =37.3211 d21 = 2.038 n13 = 1.8061 ν13 = 40.9 r22 = ∞ d22 = 25.393 n14 =1.51633 ν14 = 64.1 r23 = ∞ d23 = 2.038 n15 = 1.8061 ν15 = 40.9 r24 =−37.3211 d24 = 0.300 r25 = 17.5105 d25 = 1.000 n16 = 1.85026 ν16 = 32.3r26 = 9.1270 d26 = 28.648 n17 = 1.51633 ν17 = 64.1 r27 = −20.3224 d27 =14.000 r28 = 20.3224 d28 = 28.648 n18 = 1.51633 ν18 = 64.1 r29 = −9.1270d29 = 1.000 n19 = 1.85026 ν19 = 32.3 r30 = −17.5105 d30 = 0.300 r31 =37.3211 d31 = 2.038 n20 = 1.8061 ν20 = 40.9 r32 = ∞ d32 = 25.393 n21 =1.51633 ν21 = 64.1 r33 = ∞ d33 = 2.038 n22 = 1.8061 ν22 = 40.9 r34 =−37.3211 d34 = 0.300 r35 = 17.5105 d35 = 1.000 n23 = 1.85026 ν23 = 32.3r36 = 9.1270 d36 = 28.648 n24 = 1.51633 ν24 = 64.1 r37 = −20.3224 d37 =14.000 r38 = 20.3224 d38 = 28.648 n25 = 1.51633 ν25 = 64.1 r39 = −9.1270d39 = 1.000 n26 = 1.85026 ν26 = 32.3 r40 = −17.5105 d40 = 0.300 r41 =37.3211 d41 = 2.038 n27 = 1.8061 ν27 = 40.9 r42 = ∞ d42 = 25.393 n28 =1.51633 ν28 = 64.1 r43 = ∞ d43 = 2.038 n29 = 1.8061 ν29 = 40.9 r44 =−37.3211 d44 = 0.300 r45 = 17.5105 d45 = 1.000 n30 = 1.85026 ν30 = 32.3r46 = 9.1270 d46 = 28.648 n31 = 1.51633 ν31 = 64.1 r47 = −20.3224 d47 =17.000 r48 = −14.8821 d48 = 2.846 n32 = 1.72916 ν32 = 54.7 r49 = −8.8016d49 = 0.300 r50 = 15.1352 d50 = 4.084 n33 = 1.618 ν33 = 63.4 r51 =−7.3338 d51 = 1.000 n34 = 1.5927 ν34 = 35.3 r52 = 9.5056 d52 = 4.000 r53= −16.8952 d53 = 2.000 n35 = 1.7552 ν35 = 27.5 r54 = −13.2379 d54 =2.000 n36 = 1.72916 ν36 = 54.7 r55 = −23.2387 d55 = 0.300 r56 = 22.9913d56 = 2.000 n37 = 1.816 ν37 = 46.6 r57 = 89.7162 d57 = 15.000 r58 = ∞d58 = 6.000 (reflection plane) r59 = ∞ d59 = 4.000 (reflection plane)r60 = 22.5828 d60 = 1.000 n38 = 1.78472 ν38 = 25.7 r61 = 6.1627 d61 =3.276 n39 = 1.55963 ν39 = 61.2 r62 = 9.4965 d62 = 1.747 r63 = 13.6433d63 = 3.041 n40 = 1.60311 ν40 = 60.7 r64 = −11.6980 d64 = 29.780 r65 =∞(image position)

TABLE 7 Lens data of the eleventh embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.500  r3 = −27.1944  d3 = 0.500  n2 =1.883  ν2 = 40.8  r4 = 1.6149  d4 = 0.400  r5 = ∞  d5 = 0.648  n3 =1.8061  ν3 = 40.9  r6 = ∞(pupil)  d6 = 8.000  n4 = 1.8061  ν4 = 40.9  r7= −5.9410  d7 = 0.300  r8 = 34.5218  d8 = 1.405  n5 = 1.60311  ν5 = 60.7 r9 = −44.4283  d9 = 1.636 r10 = 10.5798 d10 = 11.910  n6 = 1.60311  ν6= 60.7 r11 = −9.6402 d11 = 1.000  n7 = 1.84666  ν7 = 23.8 r12 = 5.5533d12 = 1.354 r13 = 16.9402 d13 = 1.000  n8 = 1.84666  ν8 = 23.8 r14 =5.6237 d14 = 2.775  n9 = 1.60311  ν9 = 60.7 r15 = −11.8857 d15 = 0.300r16 = 9.6717 d16 = 2.054 n10 = 1.72916 ν10 = 54.7 r17 = 67.8305 d17 =12.000 r18 = 19.4101 d18 = 30.497 n11 = 1.51633 ν11 = 64.1 r19 = −9.3708d19 = 1.000 n12 = 1.85026 ν12 = 32.3 r20 = −18.4223 d20 = 0.300 r21 =37.3503 d21 = 1.000 n13 = 1.8061 ν13 = 40.9 r22 = ∞ d22 = 29.679 n14 =1.51633 ν14 = 64.1 r23 = ∞ d23 = 1.000 n15 = 1.8061 ν15 = 40.9 r24 =−37.3503 d24 = 0.300 r25 = 18.4223 d25 = 1.000 n16 = 1.85026 ν16 = 32.3r26 = 9.3708 d26 = 30.497 n17 = 1.51633 ν17 = 64.1 r27 = −19.4101 d27 =14.000 r28 = 19.4101 d28 = 30.497 n18 = 1.51633 ν18 = 64.1 r29 = −9.3708d29 = 1.000 n19 = 1.85026 ν19 = 32.3 r30 = −18.4223 d30 = 0.300 r31 =37.3503 d31 = 1.000 n20 = 1.8061 ν20 = 40.9 r32 = ∞ d32 = 29.679 n21 =1.51633 ν21 = 64.1 r33 = ∞ d33 = 1.000 n22 = 1.8061 ν22 = 40.9 r34 =−37.3503 d34 = 0.300 r35 = 18.4223 d35 = 1.000 n23 = 1.85026 ν23 = 32.3r36 = 9.3708 d36 = 30.497 n24 = 1.51633 ν24 = 64.1 r37 = −19.4101 d37 =14.000 r38 = 19.4101 d38 = 30.497 n25 = 1.51633 ν25 = 64.1 r39 = −9.3708d39 = 1.000 n26 = 1.85026 ν26 = 32.3 r40 = −18.4223 d40 = 0.300 r41 =37.3503 d41 = 1.000 n27 = 1.8061 ν27 = 40.9 r42 = ∞ d42 = 29.679 n28 =1.51633 ν28 = 64.1 r43 = ∞ d43 = 1.000 n29 = 1.8061 ν29 = 40.9 r44 =−37.3503 d44 = 0.300 r45 = 18.4223 d45 = 1.000 n30 = 1.85026 ν30 = 32.3r46 = 9.3708 d46 = 30.497 n31 = 1.51633 ν31 = 64.1 r47 = −19.4101 d47 =19.000 r48 = −14.3213 d48 = 7.000 n32 = 1.72916 ν32 = 54.7 r49 =−11.0960 d49 = 0.300 r50 = 33.1140 d50 = 1.047 n33 = 1.618 ν33 = 63.4r51 = 9.1082 d51 = 7.000 n34 = 1.5927 ν34 = 35.3 r52 = 67.5887 d52 =3.277 r53 = −9.9528 d53 = 7.000 n35 = 1.7552 ν35 = 27.5 r54 = 41.3894d54 = 10.000 n36 = 1.72916 ν36 = 54.7 r55 = −19.8178 d55 = 3.000 r56 =−63.2683 d56 = 7.000 n37 = 1.816 ν37 = 46.6 r57 = −41.6536 d57 = 6.621r58 = 20.1426 d58 = 2.426 n38 = 1.51633 ν38 = 64.1 r59 = −122.3553 d59 =5.000 n39 = 1.78472 ν39 = 25.7 r60 = 32.7733 d60 = 2.000 r61 = 21.5258d61 = 5.000 n40 = 1.5725 ν40 = 57.8 r62 = 563.4090 d62 = 36.001 r63 =∞(image position)

TABLE 8 Lens data of the twoelveth embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.500  r3 = −5.6176  d3 = 8.000  n2 =1.883  ν2 = 40.8  r4 = ∞(pupil)  d4 = 8.000  n3 = 1.883  ν3 = 40.8  r5 =−10.6525  d5 = 1.727  r6 = 225.1706  d6 = 1.024  n4 = 1.60311  ν4 = 60.7 r7 = 794.5057  d7 = 0.803  r8 = 7.7627  d8 = 3.448  n5 = 1.6968  ν5 =55.5  r9 = 7.0551  d9 = 1.200  n6 = 1.84666  ν6 = 23.8 r10 = 6.6689 d10= 1.754 r11 = 21.0094 d11 = 1.000  n7 = 1.84666  ν7 = 23.8 r12 = 5.2971d12 = 3.637  n8 = 1.60311  ν8 = 60.7 r13 = −17.1652 d13 = 0.300 r14 =9.0345 d14 = 2.401  n9 = 1.72916  ν9 = 54.7 r15 = 40.5646 d15 = 12.000r16 = 19.9468 d16 = 30.262 n10 = 1.51633 ν10 = 64.1 r17 = −9.0769 d17 =1.018 n11 = 1.85026 ν11 = 32.3 r18 = −18.5715 d18 = 0.300 r19 = 34.7626d19 = 3.093 n12 = 1.8061 ν12 = 40.9 r20 = ∞ d20 = 19.606 n13 = 1.51633ν13 = 64.1 r21 = ∞ d21 = 3.093 n14 = 1.8061 ν14 = 40.9 r22 = −34.7626d22 = 0.300 r23 = 18.5715 d23 = 1.018 n15 = 1.85026 ν15 = 32.3 r24 =9.0769 d24 = 30.262 n16 = 1.51633 ν16 = 64.1 r25 = −19.9468 d25 = 14.000r26 = 19.9468 d26 = 30.262 n17 = 1.51633 ν17 = 64.1 r27 = −9.0769 d27 =1.018 n18 = 1.85026 ν18 = 32.3 r28 = −18.5715 d28 = 0.300 r29 = 34.7626d29 = 3.093 n19 = 1.8061 ν19 = 40.9 r30 = ∞ d30 = 19.606 n20 = 1.51633ν20 = 64.1 r31 = ∞ d31 = 3.093 n21 = 1.8061 ν21 = 40.9 r32 = −34.7626d32 = 0.300 r33 = 18.5715 d33 = 1.018 n22 = 1.85026 ν22 = 32.3 r34 =9.0769 d34 = 30.262 n23 = 1.51633 ν23 = 64.1 r35 = −19.9468 d35 = 14.000r36 = 19.9468 d36 = 30.262 n24 = 1.51633 ν24 = 64.1 r37 = −9.0769 d37 =1.018 n25 = 1.85026 ν25 = 32.3 r38 = −18.5715 d38 = 0.300 r39 = 34.7626d39 = 3.093 n26 = 1.8061 ν26 = 40.9 r40 = ∞ d40 = 19.606 n27 = 1.51633ν27 = 64.1 r41 = ∞ d41 = 3.093 n28 = 1.8061 ν28 = 40.9 r42 = −34.7626d42 = 0.300 r43 = 18.5715 d43 = 1.018 n29 = 1.85026 ν29 = 32.3 r44 =9.0769 d44 = 30.262 n30 = 1.51633 ν30 = 64.1 r45 = −19.9468 d45 = 19.000r46 = −11.8408 d46 = 5.820 n31 = 1.72916 ν31 = 54.7 r47 = −9.1946 d47 =0.300 r48 = 24.0775 d48 = 10.000 n32 = 1.618 ν32 = 63.4 r49 = −26.2109d49 = 7.000 n33 = 1.5927 ν33 = 35.3 r50 = 63.4749 d50 = 3.000 r51 =−8.3204 d51 = 5.376 n34 = 1.7552 ν34 = 27.5 r52 = −38.8722 d52 = 10.000n35 = 1.72916 ν35 = 54.7 r53 = −19.1304 d53 = 3.000 r54 = −83.1506 d54 =7.000 n36 = 1.816 ν36 = 46.6 r55 = −41.8244 d55 = 8.346 r56 = −26.1283d56 = 4.325 n37 = 1.51633 ν37 = 64.1 r57 = −7.8805 d57 = 4.552 n38 =1.78472 ν38 = 25.7 r58 = −14.4880 d58 = 0.300 r59 = 31.7804 d59 = 5.000n39 = 1.5725 ν39 = 57.8 r60 = 6326.3883 d60 = 36.032 r61 = ∞(imageposition)

TABLE 9 Lens data of the thirteenth embodiment  r1 = ∞  d1 = 0.400  n1 =1.7682  ν1 = 71.8  r2 = ∞  d2 = 0.500  r3 = 14.7408  d3 = 0.500  n2 =1.883  ν2 = 40.8  r4 = 1.5441  d4 = 0.400  r5 = ∞  d5 = 0.572 n3  n3 =1.8061  ν3 = 40.9  r6 = ∞(pupil)  d6 = 7.966  n4 = 1.8061  ν4 = 40.9  r7= −5.9996  d7 = 0.300  r8 = 38.8172  d8 = 1.360  n5 = 1.60311  ν5 = 60.7 r9 = −54.0250  d9 = 1.040 r10 = 10.8354 d10 = 11.720  n6 = 1.60311  ν6= 60.7 r11 = −36.1554 d11 = 1.000  n7 = 1.84666  ν7 = 23.8 r12 = 5.7085d12 = 1.444 r13 = 17.6383 d13 = 1.000  n8 = 1.84666  ν8 = 23.8 r14 =5.3388 d14 = 3.339  n9 = 1.60311  ν9 = 60.7 r15 = −10.4808 d15 = 0.300r16 = 10.4139 d16 = 2.316 n10 = 1.72916 ν10 = 54.7 r17 = 1299.7086 d17 =12.000 r18 = 20.9531 d18 = 28.137 n11 = 1.51633 ν11 = 64.1 r19 = −9.0377d19 = 1.029 n12 = 1.85026 ν12 = 32.3 r20 = −17.1424 d20 = 0.300 r21 =37.8341 d21 = 1.462 n13 = 1.8061 ν13 = 40.9 r22 = ∞ d22 = 26.759 n14 =1.51633 ν14 = 64.1 r23 = ∞ d23 = 1.462 n15 = 1.8061 ν15 = 40.9 r24 =−37.8341 d24 = 0.300 r25 = 17.1424 d25 = 1.029 n16 = 1.85026 ν16 = 32.3r26 = 9.0377 d26 = 28.137 n17 = 1.51633 ν17 = 64.1 r27 = −20.9531 d27 =14.000 r28 = 20.9531 d28 = 28.137 n18 = 1.51633 ν18 = 64.1 r29 = −9.0377d29 = 1.029 n19 = 1.85026 ν19 = 32.3 r30 = −17.1424 d30 = 0.300 r31 =37.8341 d31 = 1.462 n20 = 1.8061 ν20 = 40.9 r32 = ∞ d32 = 26.759 n21 =1.51633 ν21 = 64.1 r33 = ∞ d33 = 1.462 n22 = 1.8061 ν22 = 40.9 r34 =−37.8341 d34 = 0.300 r35 = −17.1424 d35 = 1.029 n23 = 1.85026 ν23 = 32.3r36 = 9.0377 d36 = 28.137 n24 = 1.51633 ν24 = 64.1 r37 = −20.9531 d37 =14.000 r38 = 20.9531 d38 = 28.137 n25 = 1.51633 ν25 = 64.1 r39 = −9.0377d39 = 1.029 n26 = 1.85026 ν26 = 32.3 r40 = −17.1424 d40 = 0.300 r41 =37.8341 d41 = 1.462 n27 = 1.8061 ν27 = 40.9 r42 = ∞ d42 = 26.759 n28 =1.51633 ν28 = 64.1 r43 = ∞ d43 = 1.462 n29 = 1.8061 ν29 = 40.9 r44 =−37.8341 d44 = 0.300 r45 = −17.1424 d45 = 1.029 n30 = 1.85026 ν30 = 32.3r46 = 9.0377 d46 = 28.137 n31 = 1.51633 ν31 = 64.1 r47 = −20.9531 d47 =19.000 r48 = −13.4332 d48 = 7.000 n32 = 1.72916 ν32 = 54.7 r49 =−11.0047 d49 = 0.300 r50 = 17.1878 d50 = 5.837 n33 = 1.618 ν33 = 63.4r51 = 57.8341 d51 = 7.000 n34 = 1.5927 ν34 = 35.3 r52 = 38.7072 d52 =4.174 r53 = −8.1955 d53 = 6.919 n35 = 1.7552 ν35 = 27.5 r54 = −42.2429d54 = 10.000 n36 = 1.72916 ν36 = 54.7 r55 = −19.4465 d55 = 0.300 r56 =944.8567 d56 = 4.699 n37 = 1.816 ν37 = 46.6 r57 = −50.3836 d57 = 18.931r58 = 136.6914 d58 = 5.000 n38 = 1.51633 ν38 = 64.1 r59 = −21.5686 d59 =5.000 n39 = 1.78472 ν39 = 25.7 r60 = −47.7722 d60 = 3.000 r61 = 24.4617d61 = 5.000 n40 = 1.5725 ν40 = 57.8 r62 = 207.2457 d62 = 24.000 r63 =∞(image position)

TABLE 10 Lens data of the twenty third embodiment r1 = ∞ d1 = 0.4 n1 =1.769000 ν1 = 71.8 r2 = ∞ d2 = 0.3 r3 = ∞ d3 = 0.5 n2 = 1.784720 ν2 =25.8 r4 = 2.18120 d4 = 0.8 r5 = ∞ d5 = 6.524779 n3 = 1.806098 ν3 = 40.9r6 = ∞ d6 = 0.000000 n4 = 1.806098 ν4 = 40.9 r7 = ∞ d7 = 10.000000 n5 =1.806098 ν5 = 40.9 r8 = −18.90821 d8 = 2.000000 r9 = 11.34978 d9 =7.000000 n6 = 1.589130 ν6 = 61.2 r10 = −6.85269 d10 = 7.000000 n7 =1.784718 ν7 = 25.7 r11 = −9.21315 d11 = 1.757525 r12 = −5.83605 d12 =1.329338 n8 = 1.784718 ν8 = 25.7 r13 = 21.54459 d13 = 5.000000 n9 =1.772499 ν9 = 49.6 r14 = −9.87710 d14 = 0.300000 r15 = 23.34659 d15 =5.000000 n10 = 1.729157 ν10 = 54.7 r16 = −46.95906 d16 = 9.832604

TABLE 11 Lens data of the twenty fort embodiment r1 = ∞ d1 = 0.4 n1 =1.769000 ν1 = 71.8 r2 = ∞ d2 = 0.3 r3 = ∞ d3 = 0.5 n2 = 1.784720 ν2 =25.8 r4 = 2.24795 d4 = 0.8 r5 = ∞ d5 = 26.000000 n3 = 1.806098 ν3 = 40.9r6 = ∞ d6 = 0.000000 n4 = 1.806098 ν4 = 40.9 r7 = ∞ d7 = 28.856575 n5 =1.806098 ν5 = 40.9 r8 = −36.97230 d8 = 15.000000 r9 = 10.27055 d9 =13.872951 n6 = 1.496999 ν6 = 31.6 r10 = −6.76542 d10 = 8.669330 n7 =1.846660 ν7 = 23.8 r11 = −12.08426 d11 = 4.358284 r12 = −6.61021 d12 =3.807170 n8 = 1.846660 ν8 = 23.8 r13 = −10.66959 d13 = 4.004968 n9 =1.772499 ν9 = 49.6 r14 = −10.95412 d14 = 3.679284 r15 = −13.63092 d15 =8.940710 n10 = 1.729157 ν10 = 54.7 r16 = −11.40751 d16 = 9.956806 r17 =18.08889 d17 = 37.945337 n11 = 1.516330 ν11 = 64.1 r18 = −8.56598 d18 =6.671087 n12 = 1.850259 ν12 = 32.3 r19 = −23.41526 d19 = 0.300000 r20 =39.63203 d20 = 1.000000 n13 = 1.806098 ν13 = 40.9 r21 = ∞ d21 = 5.000000n14 = 1.516330 ν14 = 64.1 r22 = ∞ d22 = 5.000000 n15 = 1.516330 ν15 =64.1 r23 = ∞ d23 = 1.000000 n16 = 1.806098 ν16 = 40.9 r24 = −39.63203d24 = 0.300000 r25 = 23.41526 d25 = 6.671087 n17 = 1.850259 ν17 = 32.3r26 = 8.56598 d26 = 37.945337 n18 = 1.516330 ν18 = 64.1 r27 = −18.08889d27 = 10.000000 r28 = 18.08889 d28 = 37.945337 n19 = 1.516330 ν19 = 64.1r29 = −8.56598 d29 = 6.671087 n20 = 1.850259 ν20 = 32.3 r30 = −23.41526d30 = 0.300000 r31 = 39.63203 d31 = 1.000000 n21 = 1.806098 ν21 = 40.9r32 = ∞ d32 = 5.000000 n22 = 1.516330 ν22 = 64.1 r33 = ∞ d33 = 5.000000n23 = 1.516330 ν23 = 64.1 r34 = ∞ d34 = 1.000000 n24 = 1.806098 ν24 =40.9 r35 = −39.63203 d35 = 0.300000 r36 = 23.41526 d36 = 6.671087 n25 =1.850259 ν25 = 32.3 r37 = 8.56598 d37 = 37.945337 n26 = 1.516330 ν26 =64.1 r38 = −18.08889 d38 = 10.000000 r39 = 18.08889 d39 = 37.945337 n27= 1.516330 ν27 = 64.1 r40 = −8.56598 d40 = 6.671087 n28 = 1.850259 ν28 =32.3 r41 = −23.41526 d41 = 0.300000 r42 = 39.63203 d42 = 1.000000 n29 =1.806098 ν29 = 40.9 r43 = ∞ d43 = 5.000000 n30 = 1.516330 ν30 = 64.1 r44= ∞ d44 = 5.000000 n31 = 1.516330 ν31 = 64.1 r45 = ∞ d45 = 1.000000 n32= 1.806098 ν32 = 40.9 r46 = −39.63203 d46 = 0.300000 r47 = 23.41526 d47= 6.671087 n33 = 1.850259 ν33 = 32.3 r48 = 8.56598 d48 = 37.945337 n34 =1.516330 ν34 = 64.1 r49 = −18.08889 d49 = 15.000000 r50 = −15.76035 d50= 7.000000 n35 = 1.816000 ν35 = 46.6 r51 = −10.49216 d51 = 0.300000 r52= 19.16924 d52 = 1.000000 n36 = 1.729157 ν36 = 54.7 r53 = 10.37555 d53 =1.000000 n37 = 1.755199 ν37 = 27.5 r54 = 8.20791 d54 = 6.363656 r55 =−24.61446 d55 = 3.366619 n38 = 1.592701 ν38 = 35.3 r56 = 9.99541 d56 =9.925109 n39 = 1.618000 ν39 = 63.4 r57 = −27.28005 d57 = 0.547138 r58 =22.89857 d58 = 7.000000 n40 = 1.729157 ν40 = 54.7 r59 = 465.13444 d59 =100.501554

TABLE 12 Lens data of the twenty fifth embodiment R D N ν r1 = ∞ d1 =0.400000 n1 = 1.769000 ν1 = 71.8 r2 = ∞ d2 = 0.300000 r3 = −5.97394 d3 =0.500000 n2 = 1.784720 ν2 = 25.8 r4 = −81.88587 d4 = 0.400000 r5 = ∞ d5= 7.000000 n3 = 1.806098 ν3 = 40.9 r6 = ∞ d6 = 0.000000 n4 = 1.806098 ν4= 40.9 r7 = ∞ d7 = 5.000000 n5 = 1.806098 ν5 = 40.9 r8 = −19.02807 d8 =0.300000 r9 = 19.68776 d9 = 1.500000 n6 = 1.603112 ν6 = 60.7 r10 =−143.32901 d10 = 0.300000 r11 = 8.84970 d11 = 2.000000 n7 = 1.603112 ν7= 60.7 r12 = 205.54794 d12 = 2.000000 n8 = 1.846660 ν8 = 23.8 r13 =7.54926 d13 = 3.000000 r14 = 11.00667 d14 = 3.000000 n9 = 1.846660 ν9 =23.8 r15 = 6.70344 d15 = 2.697123 n10 = 1.603112 ν10 = 60.7 r16 =−29.22995 d16 = 0.300000 r17 = 25.03133 d17 = 5.000000 n11 = 1.729157ν11 = 54.7 r18 = −19.09934 d18 = 14.067359 r19 = 20.97714 d19 =31.002854 n12 = 1.516330 ν12 = 64.1 r20 = −9.61884 d20 = 1.000000 n13 =1.850259 ν13 = 32.3 r21 = −18.35394 d21 = 0.300000 r22 = 39.59182 d22 =1.000000 n14 = 1.806098 ν14 = 40.9 r23 = ∞ d23 = 12.733214 n15 =1.516330 ν15 = 64.1 r24 = ∞ d24 = 12.733214 n16 = 1.516330 ν16 = 64.1r25 = ∞ d25 = 1.000000 n17 = 1.806098 ν17 = 40.9 r26 = −39.59182 d26 =0.300000 r27 = 18.35394 d27 = 1.000000 n18 = 1.850259 ν18 = 32.3 r28 =9.61884 d28 = 31.002854 n19 = 1.516330 ν19 = 64.1 r29 = −20.97714 d29 =13.999522 r30 = 20.97714 d30 = 31.002854 n20 = 1.516330 ν20 = 64.1 r31 =−9.61884 d31 = 1.000000 n21 = 1.850259 ν21 = 32.3 r32 = −18.35394 d32 =0.300000 r33 = 39.59182 d33 = 1.000000 n22 = 1.806098 ν22 = 40.9 r34 = ∞d34 = 12.733214 n23 = 1.516330 ν23 = 64.1 r35 = ∞ d35 = 12.733214 n24 =1.516330 ν24 = 64.1 r36 = ∞ d36 = 1.000000 n25 = 1.806098 ν25 = 40.9 r37= −39.59182 d37 = 0.300000 r38 = 18.35394 d38 = 1.000000 n26 = 1.850259ν26 = 32.3 r39 = 9.61884 d39 = 31.002854 n27 = 1.516330 ν27 = 64.1 r40 =−20.97714 d40 = 22.951000 r41 = 51.24000 d41 = 4.900000 n28 = 1.712995ν28 = 53.9 r42 = −30.80800 d42 = 0.350000 r43 = 15.16600 d43 = 4.930000n29 = 1.617001 ν29 = 62.8 r44 = 47.26000 d44 = 1.650000 n30 = 1.592701ν30 = 35.3 r45 = 10.61000 d45 = 7.000000 r46 = −8.87100 d46 = 2.070000n31 = 1.755199 ν31 = 27.5 r47 = −42.79500 d47 = 7.380000 n32 = 1.696800ν32 = 56.5 r48 = −13.94800 d48 = 0.480000 r49 = ∞ d49 = 4.700000 n33 =1.804000 ν33 = 46.6 r50 = −45.75100 d50 = 8.660000 r51 = 47.10400 d51 =3.500000 n34 = 1.516330 ν34 = 64.1 r52 = −22.01500 d52 = 1.500000 n35 =1.784718 ν35 = 25.7 r53 = −48.13700 d53 = 1.000000 r54 = 79.15800 d54 =3.000000 n36 = 1.572501 ν36 = 57.8 r55 = −79.15800 d55 = 32.098487

TABLE 13 Lens data of the twenty sixth embodiment r1 = ∞ dl = 1.0 n1 =1.51633 ν1 = 64.15 r2 = ∞ d2 = 0.3 r3 = ∞ d3 = 1.5 n2 = 1.72916 ν2 =54.68 r4 = 4.4560 d4 = 2.5 r5 = ∞ d5 = 22.02 n3 = 1.88300 ν3 = 40.78 r6= ∞(pipul) d6 = 5.39 n4 = 1.88300 ν4 = 40.78 r7 = −10.3990 d7 = 1.02 r8= −8.6190 d8 = 2.0 n5 = 1.62004 ν5 = 36.25 r9 = ∞ d9 = 3.5 n6 = 1.788 ν6= 47.38 r10 = −14.1680 d10 = 2.28 r11 = 24.1810 d11 = 6.14 n7 = 1.51633ν7 = 64.15 r12 = −11.7470 d12 = 3.0 n8 = 1.78472 ν8 = 25.71 r13 = ∞ d13= 8.65 r14 = 38.2890 d14 = 3.0 n9 = 1.59551 ν9 = 39.21 r15 = 11.4220 d15= 6.0 n10 = 1.51633 ν10 = 64.15 r16 = −19.2720 d16 = 10.0

TABLE 14 Lens data of the twenty seventh embodiment r1 = ∞ d1 = 0.4 n1 =1.7682 ν1 = 71.8 r2 = ∞ d2 = 0.5 r3 = −12.44196 d3 = 0.5 n2 = 1.883 ν2 =40.8 r4 = 3.50665 d4 = 0.4 r5 = ∞ d5 = 7.0 n3 = 1.80610 ν3 = 40.9 r6 =∞(pipul) d6 = 7.0 n4 = 1.80610 ν4 = 40.9 r7 = −9.32306 d7 = 0.3 r8 =24.40418 d8 = 1.3301 n5 = 1.60311 ν5 = 60.7 r9 = −51.70650 d9 = 0.8047r10 = 10.49630 d10 = 10.0 n6 = 1.60311 ν6 = 60.7 r11 = −12.17332 d11 =1.0 n7 = 1.84666 ν7 = 23.8 r12 = 5.56286 d12 = 1.7183 r13 = −11.69704d13 = 1.0 n8 = 1.84666 ν8 = 23.8 r14 = −221.94536 d14 = 2.1568 n9 =1.60311 ν9 = 60.7 r15 = −8.24002 d15 = 0.3 r16 = 10.31164 d16 = 2.3746n10 = 1.72916 ν10 = 54.7 r17 = −30.38097 d17 = 12.0 r18 = 20.97714 d18 =31.0029 n11 = 1.51633 ν11 = 64.1 r19 = −9.61884 d19 = 1.0 n12 = 1.85026ν12 = 32.3 r20 = −18.35394 d20 = 0.3 r21 = 39.59182 d21 = 1.0 n13 =1.8061 ν13 = 40.9 r22 = ∞ d22 = 25.4664 n14 = 1.51633 ν14 = 64.1 r23 = ∞d23 = 1.0 n15 = 1.8061 ν15 = 40.9 r24 = −39.59182 d24 = 0.3 r25 =18.35394 d25 = 1.0 n16 = 1.85026 ν16 = 32.3 r26 = 9.61884 d26 = 31.0029n17 = 1.51633 ν17 = 64.1 r27 = −20.97714 d27 = 13.9995 r28 = 20.97714d28 = 31.0029 n18 = 1.51633 ν18 = 64.1 r29 = −9.61884 d29 = 1.0 n19 =1.85026 ν19 = 32.3 r30 = −18.35394 d30 = 0.3 r31 = 39.59182 d31 = 1.0n20 = 1.8061 ν20 = 40.9 r32 = ∞ d32 = 25.4664 n21 = 1.51633 ν21 = 64.1r33 = ∞ d33 = 1.0 n22 = 1.8061 ν22 = 40.9 r34 = −39.59182 d34 = 0.3 r35= 18.35394 d35 = 1.0 n23 = 1.85026 ν23 = 32.3 r36 = 9.61884 d36 =31.0029 n24 = 1.51633 ν24 = 64.1 r37 = −20.97714 d37 = 13.9995 r38 =20.97714 d38 = 31.0029 n25 = 1.51633 ν25 = 64.1 r39 = −9.61884 d39 = 1.0n26 = 1.85026 ν26 = 32.3 r40 = −18.35394 d40 = 0.3 r41 = 39.59182 d41 =1.0 n27 = 1.8061 ν27 = 40.9 r42 = ∞ d42 = 25.4664 n28 = 1.51633 ν28 =64.1 r43 = ∞ d43 = 1.0 n29 = 1.8061 ν29 = 40.9 r44 = −39.59182 d44 = 0.3r45 = 18.35394 d45 = 1.0 n30 = 1.85026 ν30 = 32.3 r46 = 9.61884 d46 =31.0029 n31 = 1.51633 ν31 = 64.1 r47 = −20.97714 d47= 7.004

1. An endoscope comprising: an elongated inserted section; anilluminating light projecting means projecting an illuminating lightfrom the distal end side of said inserted section; an objective opticalsystem arranged on the distal end side of said inserted section, havingat least two optical systems receiving the light from an objectilluminated by said illuminating light and forming at least two imagesnot equal to each other; and one image transmitting optical systemhaving single optical axis and being formed to be of a size equal to orlarger in the radial direction than a size of said objective opticalsystem, and arranged within said inserted section and transmitting saidtwo images in common, wherein said objective optical system has said twooptical systems arranged in parallel on an object side and one opticalsystem arranged in common on the image side of said two optical systemsand said two optical systems are formed of negative lenses.
 2. Astereoendoscope comprising: an elongate inserted section; anilluminating light projecting means projecting an illuminating lightfrom the distal end side of said inserted section; an objective opticalsystem arranged on the distal end side of said inserted section andforming n images (wherein n is an integer equal to or above 3) having aparallax between each other for the object illuminated by saidilluminating light; one transmitting optical system transmitting the nimages; at least one image taking means taking the respective imagessimultaneously; and a displaying means selectively displaying any twoimages of the taken plural images.
 3. A stereoendoscope comprising: anelongate inserted section; an illuminating light projecting meansprojecting an illuminating light from the distal end side of theinserted section; an objective optical system arranged on the distal endside of said inserted section and forming plural images having aparallax between each other respectively in spatially separatedpositions for the object illuminated by said illuminating light; oneimage transmitting optical system transmitting said plural images; andan adapter optical system for re-forming the plural images havingparallax, wherein the optical axis of said adapter optical system isinclined to an optical axis of said image transmitting optical system.4. A stereoendoscope comprising: an elongate inserted section; anilluminating light projecting means projecting an illuminating lightfrom the distal end side of said inserted section; an objective opticalsystem wherein plural optical systems are arranged in parallel on thedistal end side of said inserted section and plural images having aparallax between each other are formed in spatially separated positionsthe object illuminated by said illuminating light; an image transmittingoptical system comprising one optical system transmitting the pluralimages formed by the objective optical system; and an image taking meanstaking at least two images of the plural images transmitted by saidimage transmitting optical system, wherein said image taking meanscomprises two image taking devices whose optical axes are inclinedrespectively to the optical axis of said image transmitting opticalsystem.
 5. A stereoendoscope comprising: an elongate inserted section;an illuminating light projecting means projecting an illuminating lightfrom the distal end side of said inserted section; an objective opticalsystem wherein plural optical systems are arranged in parallel on thedistal end side of said inserted section and plural images having aparallax between each other are formed for the object illuminated bysaid illuminating light; an image transmitting optical system comprisingone optical system transmitting the plural images formed by theobjective optical system; and an image taking means taking at least twoimages of the plural images transmitted by said image transmittingoptical system, wherein said image taking means comprises plural imagetaking devices and central parts on image taking surfaces of said pluralimage taking devices are arranged as inclined to contact curved surfacesof the images.
 6. A stereoendoscope comprising: an elongate insertedsection; an illuminating light projecting means projecting anilluminating light from the distal end side of said inserted section; anobjective optical system arranged on the distal end side of saidinserted section and forming n images (wherein n is an integer equal toor above 3) having a parallax between each other for the objectilluminated by said illuminated light, said n images are notsuperimposed on each other; one image transmitting optical systemtransmitting the n images; at least one image taking means taking therespective images; and a displaying means selectively displaying any twoimages of the taken plural images.